It took me month to see an Atari 810 disc drive in the area, and I just found 2 in a couple of months. Today on Craigslist ($100) you can get an Atari 800 with a 810, both with their boxes and a few other things for $100. A tad pricey, but the presence of the boxes, that look good also, make these more valuable. Difficult to see what are the other things included, I will try to get this lot for cheaper, then will report (if I succeed).
Cool boxed Atari 800 + 810 on Craigslist
It is still difficult to find lot of discs for the Atari it seems. Maybe the name Atari plus the fact that many games were available on carts was making that computer too much of a game machine, hence people favoring carts. On the other end, the C64 was a game machine, and I can find games everywhere.