I escalated the case, and e-bay came through.
here is how it went.
end of april, bought pump, 255 bucks.
showed up, broke, contacted him, ended up opening a claim.
he told me he had no horse in this race, and I was on my own, so I open a USPS claim
I got the max insured amount, 200 bucks, plus the 15.40 of postage and insurance, so got 215.40 of my purchase refunded.
I asked him for the remaining balance nicely, he quit talking to me, etc. so I escalated the case. in the requests/ comments box, I told ebay that I had received a payment from USPS for 200, and I wanted the last 55. I was concerned, as the original case I opened wanted the whole 255 back, so I was worried they would pull the whole 255 from his account. case finally settled today, and I got 55 dollars in my paypal account from the guy, surely forced by e-bay. so now, 55 dollars.
so the grand refund total for the 255 dollar IP is: $270.40
I feel bad fudging and telling e-bay I only got 200, rather than 215.40, but figured with my time wasted and trouble I can have the 15.40, and am glad they didnt rip the other guys guts out for 255, and did as I asked in the comments box, and only took 55 bucks from him, so I fell all is fair, and we all got what we should deserved, no more, no less.
now: what should I do for feedback? should I tear him apart, leave a moderate rating, or kill him with kindness and give him a 5 star rating and put "you are welcome" in the comment box.
pretty glad this thing turned out like it did, thanks for all the advice and support everyone, it was much appreciated!