Lauren,
Your time is worth money. And how much of your time has already been spent here on line talking about this and how much of your time has been spend online with this guy? Time you could have been using working on another order, time you could have been spending on your business plan, time you could have been spending just sitting back and enjoying your free time. Instead, you are wasting time dealing with a low life deadbeat.
Is that even worth $100, much less $75. It's great for you to stick up for your ideals as CW Jones says, but the reality is this is taking up way too much of your time. And if this guy does like to sue, just think of all the fun times you'll have preparing for court and then taking time off in the middle of the day to go to court. Sure you may win, but if he doesn't want to pay, you'll spend even more time getting an injunction against him, dealing with the marshalls to go pick him up, trying to put a garnish on his wages (not sure a judge would even try a garnishment for $100 + fees).
But it's your business...