perhaps it would be wiser to keep your motor for the time being, and get an LRP or novak speed controller. then when funds become available again, get whatever motor you want
that way when you want to upgrade again you just need another new motor, instead of a motor and speed control. id personally go with a new ESC. that will put you on the road to building a super rustler. save up, slap a 12x2 motor in there, some hop ups, and show the kids at the track what punks they are for running losi
just my .02. most often the slowest route is the most satisfying!