hmm, eb xr6's start anywhere from $5000 up for a good one, EF xr6's start from $8000-$9000 upwards for a good one, as for insurance... ha thats a good question, i dont wanna touch that one wif a 50foot pole. lol alot of $$$ i guess..
if i was in your position i'd be buying a dead stock eb/ef in good condition, then doing mods 2 it. eg, get a 5spd EF sedan for around $8000, put a tickford snorkel on it $25, k&n filter $120, extractors $400, exhaust $200, and you will have a reasonably quick car. maybe down the track you could get some mags for it and a ef xr6 body kit. and this way insurance wont be as much.
anyways, goodluck man.