This has been theorized by his brother and others, but I'm not sure he ever claimed that. He wrote a lot of words in a pretty famous document as to why he bombed his targets, none of which were federal government targets.
Ted Kaczynski didn't bomb the federal government though.
I'd also be curious about a citation for his motivation being the MK Ultra experiments, it's news to me that he ever explicitly called those as a motive.
I'd say you got a good deal getting two dollars instead of life long trauma.