That is a tough call.
The V2 will save you some $$, but the MiniMe has the AD converter which is definitely nicer than the AD in the JB3.
That being said, I bet you can find both pre-owned for fair prices (~$625 for aV2 and $800 for a Mini with No USB) which would give you a fantastic sound since the pre/gain stage in the MiniMe is not the best you can get. Talk to Tim or SGordo or Crouch about that....
Upgrading your mics is still your best bet! I know of some tapers using the 300s with a MiniMe and were not too impressed after a while.
Just my 2 cents
Phil