On a small indoor carpet track, I was only 6/10ths behind TQ in round 2 on club meeting friday, with a brushed stock motor and nimh, against 13.5 with lipo. (I didnt improve my time for r3,and got put back to 3rd).
Granted I have been racing 15 years or so, but if you have a well setup car with good car control, you shouldnt let cost come into play too much.
It does make things easier though having brushless, no doubt... (Mine is on order
)