I have paid more & salvaged from worse so from lots of experience I can tell you that you are buying a lot of work. In an average year I scrap about 25 machines like this a year and it isn't as bad as some people are trying to make it sound but you do have to "work smart".
Typically I have plenty of gloves around and masks - I never bring machines with mold into the house - all salvage work is done outside. I save what I can and then move on to the next machine. It doesn't take many parts to get $100 (or more) out of a machine. Typically a chime box, lock bar, and plastic set is worth more than that. The key is save what you can but don't obsess over the rest. What ever you save is going to help bring other machines back to life.
Some people are afraid to get their hands dirty and I fully understand that, but other "slightly crazy" people (like myself) love to save parts off machines like this. I doubt you will be saving any of those machines but it is possible once you get them out and take a hard look at each. Just remember - lots of work for very little financial return in most cases - and if you are OK with that go for it.