If you want something that's already electric, there' aren't many options. The Caster F8T and AE RC8Te are the only electric truggies I know of. If you don't mind building something yourself via a conversion, you have a alot more options. The Caster F8T RTR is probably the easiest route. $525 shipped with everything to get it running from holeshot...that's almost impossible to beat.
A MMM isn't $350...they can be had for $270 if you search around. But you don't NEED an MMM. If you don't mind used, you can find a used Losi 8T or Mugen MBX5T and get a conversion kit (Tekno kit is the nicest IMO...very complete and placement is well thought out). You can build up a nice setup with a 2.4GHz TX/RX for $600. If you need an MMM, I don't think you can get the BL setup, servo, and TX/RX for under $600 with a new truggy to convert.
If you're interested, I'm selling my Losi 8T 1.0 with a Tekno conversion on it that has 1 run (didn't even discharge the pack). The Tekno elektri-clutch is still brand new, as are several parts that I picked up (front and rear center diff bulkheads, center top plate, spur gear, etc.). The electronics I have on it aren't included (need those), but you get the 8T 1.0, stock chassis, a ton of spare parts, a body that's in fine condition, and a virtually new Tekno kit. PM me if you're interested.