I'm not just saying this because I personally prefer Associated vehicles but, you made a good point about the Prolite truck. It's 4x4, brushless, RTR, made by Associated, can be raced effectively at club tracks or bashed at the local park just the same and the price is reasonable. It sounds like a very solid option to consider. As you noted, the Slash starts at $450, a Losi Ten-SCTE is about the same price, HPI doesn't offer a 4x4 SC unless you look at the Apache 1/8 which is about $600.
Otherwise you can talk to nitrosportsandrunner about what Redcat options are available in that range. If you're so inclined, you can pickup an Ofna NeXX roller for about $250 and install your own electronics.
Buy it from
Tower Hobbies and use code 016AP until the end of the month and it discounts the truck $20.