LauraAnn, part of the problem with this is that my FIL did NOT save up the money for and pay for this trip, my MIL did!! Yes, they are married, but for some reason they keep separate money (always have???)
In any case, I believe my husband got some of his thinking FROM his father and that is why his father didn't say "you can pay me a little less, I just want you to go on the trip". It aggravates me, but my MIL told my husband that if he didn't want his kids to see him how HE sees his father, maybe this was the time to start putting OTHER things other than just financial support as a priority. This is exactly how FIL was when DH was growing up...and he HATED IT. I think that talk with his mom is what really made the difference.
I'm just overjoyed that he will most likely come, it wouldn't have been the same without him.