To be honest, facts and figures, alexa, google results dont mean an awful lot IF an end-user WANTS a name...
If somebody wants your name and has to have the .com then your the man.
Sure, you bought it for reg fee so its a nice turn.
However, the terms work well together. Franchises are an ever growing sector of SME and its a good name within that sector.
I'd keep it and create a mini site with adsense, add franchise articles and try and get direct Franchise Ads on it.
The only thing that worries me is that the $100 is such a rubbish offer it may just be another reseller or small-time developer looking to do exactly what I mentioned above.
Hitting them with a high counter offer will either show their trule colors or scare them away. Only you can make that call. How much do you need the $100? It could buy a lot of other reg names. These should be your biggest factors on whether to sell or not, especially if you haven't got the time or knowhow to develop it IF they dont take the counter offer.