I've been in a long running 5e game. There's only one original character from that game still being played, and the character has made it to 17th or 18th level. At some point, the GM switched over to using Sane Magic Item Prices. It's kind of a pain, since the longer the game runs, the more out of date the Sane Magic Item Prices gets, as more magical items get added, while Sane doesn't get updated.
The bigger problem is that at some point, the GM started cutting back on the amount of treasure we get. I haven't talked to him about that, but I'm guessing that switched over to DMG recommendations or something.
Now, we can't stay afloat. There's not enough gold coming in, and the magic items are just too expensive. My present character (Changling Bard) started at 4th level and is now 8th level. She started play with Glamoured Studded Leather as her magic item. Since then, the only additional magic item I've acquired has been Goggles of Night, because another character took pity on me.
Maybe it's just a problem with my group, but I think it's actually the DMG advice (don't give out treasure) coupled with the Sane Magic Item Prices (overcharge for everything). But I'm very interested in what others have to say about this, and what solutions you've come up with at your own tables. I'm planning on GMing my own game soon, and would rather not have my players endlessly frustrated by not being able to afford magical items... or looking down at their character sheet and having to sheepishly say, "I can't afford <basic expense>... I'm broke."
I recently downloaded the
Magic Item Management supplement that Matrix Sorcica posted. The prices there, for the most part, are quite a bit lower than the prices listed in Sane. Plus it's a more complete list, with items up through Tasha's being listed. The list isn't perfect, I've ran across a few missing items already, and have seen a few typos. But it's probably going to be what I'll be using when I start my own game.