So what kind of performance increase will I see with a pipe, and what kind of expense should i expect.
Probably the best overall boost in performance for the $$$ outside of a new prop.
If you can afford it, the one that most people go for is Factory Pipe's Limited B-Pipe, but even used ones go for $500-600, and are snapped up almost as soon as they are posted for sale.
Be warned though, the big issue with used pipes is the adjustment screws in the head pipe.
A Pipe, Prop, and grate are really all the mods needed for most people as far as a blaster goes.
I have seen a Blaster barrel rolled and backflipped with no other mods than these 3 items.
When buying a prop, be thinking about if you want top end speed, or off the line pop, as the two tend to be in oppisite directions for prop specs.