Charles Bukowski - American author

Okay, we know that they were friends. I've read my copy of The Bukowski/Purdy Letters, (thank you mjp) and I'm about to re-read it.

I'm very much going to try to find his poetry, books, word, etc.
Where do I start? The Caribou Horses?

I can't really find anything very cheap on abe.
Am I looking in the wrong place?
where can I find his books?

Any ideas/input?

-HC

p.s. forgive me if this thread already exists...but if you would be so kind as to point me in the right direction.