Zazzle has a 40% Off Posters sale that ends today with code JUNEBLOOMZAZ which is potentially a good opportunity to order some of the past posters too.
The default poster print is 24"x24" for $18.75 you can change the size up or down 12"x12" is only $9.85. And with the discount today it drops even more.
I also recommend for smaller prints considering the heavyweight archival paper it is easier to mount and lays flat even if just hung.
All of the designs back to Cturtle are availble if you want to take advantage of the sale right now: