US Space Station Cuts Hurts Canada's Space Science
I believe your trying to argue that since the USA paid it's contractors a larger sum of money than other countries that they should have sole ownership of the station. This seems unreasonable as the USA signed agreements to provide its partners with access to the station with prior knowledge of how much each country was contributing.
The USA would no doubt not care that it is paying more because the $25 billion it budgeted was going to US contractors, and many of the partner countries also paid substantial amount to US contractors. A boost for the US economy all the way around. Pay $25 and get $30 out of the deal!
Now the dollar figures I don't think can be compared directly without in depth analysis. The USA has a history of overpaying, sometimes in the extreme, aerospace contractors and have had many failures in space recently. I think many suspect ineffeciency and ineffectiveness on the part of the USA in this endevour. What would the European nations or Canada delivered for US$25 billion? Would it have taken as long? Would they have been more effecient? It would certainly be in metric! ;-) Perhaps the USA did do a good job, however no one here can determine that. It's not possible to reasonable compare each nations contribution.
Each nation did contribute, and they had an agreement as to how the station would be used. The USA economy got an economic boast from the construction of the station. It got countless billions from it's own government, and more from other governments as well. The US economy has benefited, and now it's government refuses to provide the partners what they agreed to. Their breaking their word.