Probably the best thing you can do is take a look in your local Craig's List to see what similar machines are selling for there.
The Singer is a model 66 and takes class 66 bobbins and standard sewing machine needles both of which are available just about anywhere. Running machines are worth more than ones that need work. Around here you might get $25 to maybe $50 on a good day for the Singer and around $35 to $50 for the other. In my market portable machines sell better than cabinet machines but that may not be the case everywhere.
Rodney