Outside of auction house prices, a lot of the prices have fallen. I've had
2 by Bukowski on eBay for a year and dropped the price several times (it's $900 now), no one has even asked about it. 8 or 10 years ago a couple copies of that sold in the $1500 range.
You can still get a decent price for manuscripts and some of the books with paintings. Normal manuscript prices seem pretty stable, and only down slightly from the days - probably 15 years ago now? - when a pair of deep-pocketed eBay bidders drove them to artificial heights (you could easily pick up all the 70s and 80s poem manuscripts you wanted for $100 to $300, sometimes a little more, then those two showed up and manuscripts that were selling for $300 sold to them for $1500, etc.). But you saw what happened at a recent auction when older manuscripts (50s and 60s) sold for very high prices. People will still pay for rarity.
Having said that, I don't know if there ever was a bubble. As far as manuscripts are concerned, I think the price was artificially
low for a long time because Scott Harrison unloaded a couple thousand manuscripts over the period of a few years. So it was the opposite of a bubble, it was a glut. Again, until the grudge-match bidders came in late on the scene.
But I don't think the truly rare things are overvalued now, or ever have been. I think paying $5000 for one of those 50s manuscripts in the recent auction was smart. I certainly considered a couple of them (until I remembered to add 25% to those bid numbers). As time goes on and supply dries up, which it pretty much has as far as manuscripts go, those things are only going to become more valuable.
The manufactured rarities, not so much. I don't think Martin's signed, numbered, diamond encrusted
things are ever going to be worth more than the early chapbooks. Then again, I started this saying that I can't sell an early Bukowski chapbook, so what do I know.
And for what it's worth, anyone who was
speculating on Bukowski items...I don't get it. As a purely speculative buy, it's pretty stupid. You're better off betting on pork belly or lard futures. I never bought a Bukowski item just to flip it. I wanted to have each of those things. But like a lot of "things" they just get sold over the years for other reasons.