I got a couple of those 486-PCI boards from eBay, one was from the Ukrainian sellers a while ago (it was considerably cheaper than it is now), packaging was sub-par (no anti-static bag, it came wrapped in paper and cardboard) but it made the trip across the ocean safely and has been working very well, it looks pretty much brand new.
The other one I got in an auction, I was the only bidder and got it for less than USD 20 including shipping, but it is a rare case, it was mislabeled as "496 system" or something like that so it didn't get much attention 😁 .
On the other hand, a few weeks ago I was watching a very nice MSI board, but the auction skyrocketed to about 100 dollars!!! 😲
So my suggestion would be to keep your eyes open and most of all have patience if you can't get anything locally, prices on eBay are inflated way out of proportion for these things nowadays but there are still reasonable sellers around if you resist the retro urge!