To start with, you won't need anywhere near 5k per toon in gear to start doing heroics smoothly, so there's a possibility you could do both.

Having said that, if it comes down to a choice, I'd personally choose gear. I'm not a big "fly around and do dailies for cash" person. I have enough to do the things I want, and what I want is to run instances/pvp/etc. You don't need epic flyers for that.