I got a few from Yourduino at 5 for 75 cents,
http://yourduino.com/sunshop2/index.php?l=product_detail&p=312
Circuit and datasheet are here,
http://arduino-info.wikispaces.com/Popular-ICs
but I had to wait until I got enough other parts to justify the shipping, ended up spending $30-some. Everything came back but be aware that whoever makes the chips has the names and info molded into the top instead of painted on. One one hand the label won't rub off, OTOH it's hard for old eyes to read even with a magnifier! I haven't tried but maybe painting the top with whiteout and then scraping will leave the stuff in the grooves. It's that or I crank up the printer-scanner at 600 DPI to see which chips I want off the foam!
But hey, at those prices I get more for my dollar even with the shipping. Not just chips, but support with full explanations.
No, I'm not part of Yourduino or related or in the same state as anyone from Yourduino. I just like the deals so far.