Here you go:
This place has the K6-2+ at 450MHz for $34.99, and if you check out the other pages (there a 3 total), one of them has a 475MHz version, but for like $49.99--not worth it in my opinion--especially since one can software select the multiplier on the 450 MHz--provided you've got enough cooling to not fry it!
BTW, the AMD K6-2+ (or K6-3+) are *not* a drop in replacement--search the "IOpener Technical Reference (Moderated)" for how to do that hack--if you haven't already.
One final thing--I'm sure you've noted this is the "2+" not the "3+". The only difference between the two is the amount of L2 cache. On the 3+ it's 256KB, on the 2+ it's 128KB--so unless you want to pay the difference between the $159 you found for the 3+ and the $34.99 for the 2+, I'd say the 2+ would be fine. I ordered 3.