Out of interest, can I ask.... the midi components.... did you provide them or did the producer? Are they pre-rendered or are there real instruments or VSTi's involved?
There are pro-studios in Nashville that would do you a similar recording, with real session musicians for less.
I will say that there are a lot of ifs and buts. For example, did you write the full arrangement? Did the "producer"? Is there a royalty percentage involved or is it all fee based?
Either way it's way more than I would pay for a home anything unless the home studio was pro level and the producer had a reputation and good contacts. With all the issues you describe i would be taking my interface and pop blast screen and going elsewhere... at least to a producer that could get his gear to work. As it was his home studio, how did he not know about the radio crosstalk? if his ears are any good, how could he miss it? Sounds like his gear might not be properly earthed. you can get the same issue wth poorly earthed guitar pick ups too.