Best place to buy a headset (A20's)?

I am looking to buy a pair of A20’s and I can’t help but notice you can buy them 100 different places. Sporty’s, Pilot mall, Amazon, Bose direct just to name a few.

My question:

Is any one of these places best to buy from? I plan to apply for the CFI rebate if it makes any differences as I know it has to be from an “authorized Bose dealer” for that to apply.

The only difference/benefit I see is maybe a 30 vs. 60 day return policy and some websites charge tax where as some don’t (which is about $70 so thats a big deal).

But other than what I said above, where is the best place to buy a headset and any benefit of one website over the other?