The top of the line Spektrum radio system (for land rc's) is the DX3R. Although the DX3.0 is a great budget system. Retail of the DX3.0 is about $260, or at least thats what most places sell it for. I got my DX3.0 brand new on ebay with a Buy it Now price of $160, which is the price of a DX2.0 at most stores.
You just have to look around for the best deal. But its hard to go wrong with almost any 2.4ghz radio system.