higher end jazz vinyl: where to turn?

I'm a lifelong jazz listener but only new to entry-level hifi, as presently marketed--by which I mean Rega p3-24 turntable, Linn Classik amp, Vienna Acoutics Mozart Grand Speakers, and a lot of heart.

Anyway I have a choice set of old ECM records, Miles Davis records, and so forth, that I bought in the early 1980s. Most of them have some noise and crackle now and again--which I largely discount as the distinguished marks of age and memory. Nonetheless a clean sweet classic jazz LP played at substantial volume, even through a low midfi system like mine, is a beautiful thing. Beauty is a rare thing, I read somewhere. And it makes me wonder about upgrading the vinyl.

So here are questions:
1. Are these $50 classic content and such rereleases of Blue Notes really so good? Including worth the effort of getting up and turning the 45 over in middle of a strong Coltrane solo-a double indignity, to a genius and to the lazy.

2. What to say of all these 180g and 200g re-releases at higher prices versus the $10-20 unopened recent copy meant for mass market (or as massy as the jazz list allowed/allows)?

3. I'm using Disc Doctor record cleaners on my old and newer vinyl, but wonder how great the different is to move to a machine, say vpi 165?

4. I'm just a poor righteous teacher so I'm a bargain hunter: an Inexpensive Audiophile down with the feel of the Expensive Winos aestheticist mentality.

5. Thanks!