I got my .5 at my LHS for $259. Calif and San Diego County sales tax was a killer at 8.75%. I don't think you're going to do much better than
this. It seems to be the best going rate online.
I went with a
Hitec analog MG servo for about $30. You can go
digital for a little bit more.
Batteries: run what ya got or get some
Lipos of you are feeling adventurous/
Looks like Mike has the 1/8 inch bore mod1 pinions back in stock for $12. And the 46t Kysoho spur set me back another $5.
Everything else I had in hand already and cannibalized from my T4. MM 4600 system and Spektrun Rx.