I was thinking along the same line as you when I started pricing an EXO build. You would definately want to use quality equipment. Even in my estimates without a new radio system I was looking at $225-$250 for a Tekin brushless system, $80-$100 for a quality Futaba, Hitec or Associated servo plus maybe another $70 for a new FASST receiver if I didn't want to take one out of my other cars. Then $40-$50 or so for a Turnigy LiPo on top of the $350 kit. It adds up quick. But, the EXO is a cool looking vehicle and there really isn't anything else quite like it on the market besides the Apache C1.
If you're looking for a 4WD brushless basher you can consider some alternatives that I thought of. 4wd Stampede VXL, a RTR brushless SC truck like a SC10 4x4, an HPI Bullet ST Flux for $350 (this probably isn't a bad alternative
http://www3.towerhobbies.com/cgi-bin...&I=LXBPVU&P=ML).
Here'sa search for HPI Flux producs on Tower:
http://www3.towerhobbies.com/cgi-bin...AdvancedSearchSome of these may be worth considering. Sign up for the Tower club which I believe is still $10 a year and you'll receive a discount plus free shipping on any of these models.