Hobby King is right now running a free shipping special on many of their items. I don't know how long it will last, so hurry if you want to order anything. https://hobbyking.com/en_us
Hold on buddy! Don't worry about electronics and batteries till you have a hull ready to install them.
I agree with Beaver. Spending 50$ to save 10$ right now at your point in the build process would not be prudent.
Hobbyking also seems to be having a decent sale on their battery packs, the Zippy packs that are popular among some on here were discounted about $10 last I checked. Bought 7 or 8 of them, 11.1v 8ah.