A pragmatic view of cartridge expenses / many questions

If you are looking at TCO, Van den hul's have 2 advantages:

1) They have a special shaped tip that supposedly lasts between 25-3500 hours, 25% or more longer than ellipticals and the like because of the way they sit in the record groove. Mine just completely wore out after 9+ years (definitely over 2500). There was no degradation of sound until the very end when it sounded terrible for one song and then wouldn't track at all. This benefit is for all VDHs, not just the most expensive ones.

2) Van den hul services them and brings them back to original condition and only charges for what is needed supposedly for a very reasonable fee. Since the ugly virus, shipping in and out of the Netherlands is an unreliable venture so they bent over backwards and replaced it with a brand new one for not much more than a complete service that assumes replacement of all wearable parts. I think this is due to their new US distributor, VPI, really emphasizing customer service and satisfaction. A pleasure to deal with - even with a person coming in with a table from their competitor, Rega (luckily, I live within an hour of their offices - a really cool place). If I ever look to make a tt change, they will have a new client, assuming they can get their gimbal arms to be competitive with Rega. 

A non-economic advantage - VDH cartridges simply present the music as intended IMHO - accurate, fast, and tight. Not warm, lush, dry, humid?, crisp, or whatever coloring terms you like to use or may like. If you want it to sound like live music in a studio or real live music from a live album, they are a great choice. And a dealer told me that in a system that they won best in show in the last year - cost no object, the cartridge and phono stage were higher end VDHs, part of a $400K system that supposedly beat multiple $1 systems. 

Just one caveat, pindac. There are some proprietary elements which are not available to anyone but the manufacturer, e.g. platinum magnets used in higher end Koetsu's. No way, I would think, to duplicate that, and several approximate substitutions of different elements would be an exercise in R&D. Not that I'm against it, I prefer DIY, but it's not always plug and play.

When listen to the records, the entire pass has too many points that contribute to the correct reproduction or severe loss. Different cartridges has different electrical and mechanical specifications. These specifications constantly change and degrade with every record played. Unlike digital, when you can hear the same sound again and again, Analog (LP) will play the same record differently with wear and tear effect included.

A cartridge can track and reproduce information from LP even with 10,000 records played, However, the lifespan of diamond stylus is limited to 500-1200 hours. It will play after 1200 hours, but the faces of a diamond stylus will change the shape and it will produce distortion within the actual sound pattern. The longer the stylus used, the less soundstage separation, correct mid-high harmonics and eventually mono-stereo will be produced. Cheap and low quality MM styluses can hold on 50-300 hours only. But from some posts on Audiogon they are "GOOD FOREVER"

The dempfer and suspension could hold on up to 20 years, but have no correct proven functioning pass 2 years.

This is reality of phono cartridge building/using. Also most of the producers would say opposite to protect their sales. After all, not many people could invest $5K-$10K in new/upgraded cartridge every 2-3 years.     Making Aidas cartridges, the most challenging task was to find the correct dempfer material. We spent 5 years experimenting with numerous manufacturers, producing our own composites ets. Still in the process, but we got probably the best dempfers on the market, that we actually can tune our cartridges to needed specs. Some materials we got hold on specs already for 5 years. There is a hope...

As the van den Hul for 5 years and the current Phasemation US agent, I would like to share what I know to be true.
i have recommended that normal life of a stylus 1500 to 2000 hours or use assuming that it set up properly.(anti-skate and azimuth and SRA)
van den Hul recommend tracking weight at 1.35-1.5 gram you should get another 500 to 1000 hours 
The suspension is made out of elastic materials Just like there is no NOS rubber tire suspension elasticity changes over 
If you treat your cartridge properly you should replace the suspension when you replace your worn out stylus. If you have an old cartridge with low hours if it 10years old replace the suspension The rubber get hard and brittle
I hope that helps

I am in agreement that there are going to be Cartridge Brands that might prove to have a requirement for a part that is only obtainable through the Manufacturer, or a Second Donor Cartridge.
My experience was as sure footed as one could want.
The Technician is known for their Workmanship and
their Freelance History of working on the Cartridge Designs for a Cartridge Producing Company.

No work is to undetaken until a suitability check is carried out through a a pre' rebuild Inspection.
There is a chance the the Technician carrying out the Inspection may have to report back that a certain part is in a condition that is unusable and the rebuild will not work to the level of the required Specification.
( I know this is a possibility, as I know of Cartridge Owners who have been supplied this information) 
This Service when used myself, does not produce a Cartridge that will Play Music after a Service like some known Services, which in cases proves to be a lesser quality than the Manufacturers Original Product,
but has a sound quality that is perceived as improved over the poor condition Donor Cartridge that received a treatment.

The rebuild Service used by myself, is a Rebuild Service that will supply a Cartridge in its Original Build Spec, but having undergone extensive Quality Control Measures, from microscopic intensive cleaning, through to replacing the Parts with Manufacturers Parts, followed up by multiple hours of measurements and adjustment, to ensure the Cartridges Specification is exact.

Or in my case, the Rebuild Cartridge is Producing a Cartridge that has the original Generator Coils retained, with a complete exchange of Parts
that are used on much more High End/Exotic Models,
each configuration being chosen, is selected with the Technicians understanding through discussion with the Cartridge Owner preference for the Cartridge Presentation.
The Cartridge will undergo a Microscopic intensive cleaning, along with the  Rebuild, and on completion will put through multiple hours of measurements and adjustment.

I have become a fan of this Technicians work, and after having investigated as much of his Rebuilds as possible through Web Searches can only say he has many supporters.

To help the OP with their investigations, I have sent a PM to show them the contact for the Rebuild Service and assess the supplied information for accuracy.