Invited to go Rallycross - need a cheap buggy

[Flodjy]

Hey guys
A friend has invited me to Rallycross with him this year. He takes it quite seriously (he's bought himself an MP9 for this season)

I've said I'd go along with him but don't want to spend too much as I know nothing about nitro and am just looking to go along for a bit of fun.

Was just going to buy an Rtr with a 21 engine and use my own radio - was looking at an HPI trophy 3.5

My question is, is this going to be completely uncompetitive along the lines of turning up to a 1/10 meeting with a Grasshopper, or will it be ok to race and have a bit of fun with.

If not - any suggestions?

Like I say, I'm not looking to go all out, just want to come along for the ride and have bit of fun