I think a little less than $100 for the Franklin would be OK. They are really good machines, and the cabinet should clean up well as long as there's no water damage. If there is, then negotiate down...less than $80, say.
The other one looks great, but I wouldn't pay more than $125 for ANY treadle!! Unless it's the most rare of all models....and even then.... Treadles are really very common, and even though they are asking high $$, if you offer less, and then keep after them, they usually will sell for less. No one is getting full asking price....unless, of course, it is that elusive favorite of yours that you have been looking for...and even then... ???