Certainly not much in interest since it will take over 44 years to pay that amount at $100 per month.
Which law do you believe is being broken? Please cite the particular statute by number and also identify your state.
I don't really understand this. You started by telling us that the "county has put [you] on a payment play until the year 2060 at $100 a month." You then told us that you contacted the "clerk and comptroller . . . to see if they were willing to settle out." I'm not entirely sure what you meant by "settle out," but I assume you were asking about making some sort of lump sum payment. Correct? Regardless, your inquiry generated a response that the county is willing to settle for $107,484.06. Nothing about that says to me that the county is "not honoring" the existing agreement for you to pay $100 a month until 2060. As you have described it, the county's response is simply that, if you want to pay this off in a lump sum now, rather than following the $100 per month plan, you'll need to pay $107k.
No one here has any idea what abilities you have, but I strongly suspect that you "can do" a great many things. I think if I were you, I would respond and say, "No thanks. I'll stick with the existing $100/month plan." Or, I suppose you could make a counteroffer, but I obviously have no idea what amount you might be able to offer or whether this unknown county in an unidentified state would be willing to negotiate.

