With posters anyway, I need the physical object straight from the artist. Feels more authentic. (Then again that's the same reason I like to buy records/CD's whenever I can because I like the romantic idea of having a palpable art object in my hands. Again, feels more authentic.)
And, in case this information is useful to anyone (may someone having to email this themselves), but I emailed Jay Ryan, artist of the Pavement poster about whether the posters would be sold and I got a really quick response saying the following:
"hi brett -
the band will have copies, though i don't know if they'll be selling them at the festival or not. my copies (all 40 of them) will be on my site at some point during the days after the festival.