jax2 is correct. Mods done well are a very worthwhile improvement. If you can not do them yourself, then the aftermarket folks are a good way to go. the only word of caution I will offer, is you usually won't get your money back out if you mod a cheap piece and then try to sell it.
More expensive gear will usually give you a better return.
Also depends on what mods were done.
As an example, I have cheapie Parasound Zpre1. Sound quality is so-so in stock form. Add 400 dollars worth of vishay resistors to it, upgrade the coupling caps; and another 150 bucks for an oversized outboard power supply, and all of a sudden you have a reference quality line stage pre amp, that will compete with some really serious gear.
Now if I were to decide to sell the mod'ed zpre, I doubt I would get much of my money in parts back out of it, since everyone thinks its just a in house music piece.
More expensive gear will usually give you a better return.
Also depends on what mods were done.
As an example, I have cheapie Parasound Zpre1. Sound quality is so-so in stock form. Add 400 dollars worth of vishay resistors to it, upgrade the coupling caps; and another 150 bucks for an oversized outboard power supply, and all of a sudden you have a reference quality line stage pre amp, that will compete with some really serious gear.
Now if I were to decide to sell the mod'ed zpre, I doubt I would get much of my money in parts back out of it, since everyone thinks its just a in house music piece.