While I have sympathy for the seller, he should understand that your bid was based on a $75 shipping quote. So, theoretically, the auction would have closed $75 less had he given an accurate shipping quote. He should accept this reasoning.

To explain my sympathy: I've shipped with FedEx, knowing the 130 dimensional limit. Several times the box has come in just at or under 130, but they always over measure. Never once have they mentioned the limit; they simply offer the shipping quote and shrug their shoulders. Once I insist they measure the package again, they get it right. Why he let it go through at $150 is beyond me, unless he prepaid with a credit card or account and had it picked up, which would result in the oversize charge being applied without him present.