If you can buy a Sp 1 for $339 at Ultimate Hobbies that is an awsome price.
I bought a used SP1 off ebay and then bought the needed upgrades (chassis, center uni's, and steering linkage) that is all that is needed to upgrade to the SP2. I spent a total of $80 to upgraded buying the parts off ebay. That would put the total going that rought around $419 for a SP2..... I have one that has every hop up on it including Racers edge f/r shock towers and hubs, chassis braces, carbon fiber top plates, and more and I have spent a total of around $470 to have the car which is now an SP2. I owned all the cars out right now and so far have liked the SP2 and the Jammin the best overall.