I honestly have no problem with Wenger not buying a striker if he doesn't want to spend 50m+ on an old-ish striker coming of an ACL injury. but that's only because just about every other position in the team could be strengthened, significantly.
if it was a question of spending 50m on Khedira, Remy, and Griezmann vs. Falcao, I would probably take those three over Falcao.
to spend nothing? well, that's exactly what I expected out of Wenger. already turned Cazorla into Arshavin 2.0, well on his way towards doing the same with Ozil.
oh well. I believe in Sanogo, I only doubt his ability to not get injured.