The limit in Minnesota is $7,400
http://www.consumeraffairs.com/consu.../small_mn.html
And no, a judge would not be biased towards a local person (at least, they shouldn't be since judges are suppose to be fair, objective and unbiased).
And for future reference, it is probably not a good thing to buy a CAR on Ebay. You would want to go it checked out by a mechanic first before you buy it used like that.