I have an A2 from Jack, it's a no brainer!!

You have to look at power use, its important. A2 uses the least power by a large margin.
I would buy one now. and another after the 1st. Once Zeus and GAW start to ship we should see some prices come down.

When you look at miners, I'm sure you saw the various spreadsheets around here. If they aren't shipping in the next 2 weeks I pay them no attention. I'm sure the DIFF is going to go up with all the new miners going online in the next few weeks. I think we are safe with the A2's until Sept, if and when KNC 300's ship. That's when the DIFF will go WAYYYYY up. You might even want to save your money on the #2 A2 and wait for the KNC. However, you should get one A2 for now.
-bobby