I'm currently running a EC Speed ESC + 11.5T motor I got for £52 by eBay auction. The same combo is available on the
EC Power website for $120. It looks similar to the 60A EZRun, but sensored.
I've run it a few nights now with a BJ4, and it's performed admirably - I had to dial down the punch as it was causing the car to torque steer on a slippy floor (or else my car has an issue, which is likely too...)! The fan is much better than the Losi system (most of the ones at my club look like a sweet-toothed hillbilly), and keeps everything nice and cool.
The little program card, similar to the EZRun efforts, works like a charm, too.
Other budget options - Roundabout Toys are selling the Orion 70A Vortex for £40 - I believe it's a redadged Xerun? It runs sensored or sensorless, so lots of options for motor.