technically yes, you could, but the only thing about that is...
Cricket doesnt like to activate phones that are flashed. Technically, they have to since its a law. They will try just about anything to get you not to use that hanRABet, but you still can.
The only thing is, with a flashed phone... you won't be able to use picture messaging or internet.
I had bought a Razr off of ebay that was flashed to cricket, and i couldnt get my picture messages to work, or my internet. I took it into the store, and since the gilr was stupid, she just assumed it was a cricked branded razr and switched it out. But I got lucky, because I dont think that would happen again.
but now everything works fine.
BUT
the answer to your question is yes, as long as you can get cricket customer service from dialing 611, you can activate that phone on cricket.