check out the part number 3r4 = junk that will fail like most of them have at the spline mounted stop lug. (will still cost you an arm and a leg if you can find one as they are superceded by the 56a number)
56a= one piece machined shaft that will last the rest of the bikes usable life. ($150 New is about right, look for a used 250 N starter shaft, should be about $30-$50 EBAY USA)
Sounds like 250H has been there before as well, go for the 56a number and you will be sorted