The best advice I have is what I wish I got to avoid a lot of unnecessary steps throwing money away.

Try your best to figure out where you want to be, just a better Tx? Better sound? Better functions?

Each upgrade has different options and not necessarily more expensive, just different or better paths.

By the way, a lot of people start out saying the don't want IR until they have two or three and get bored just driving around. Battling raises the enjoyment of these things exponentially, and you live in an area with a few tankers around.