My dad is a recently retired prison guard. Since he worked for the state, in a maximum security prison no less, he got to retire after 20 years service. So he retired last April, and since then he's been working odd jobs (since the pension doesn't exactly cut it for a 4 person family).
Most frequently, he works with his friend's tree service, doing exactly what you're talking about... cutting down trees, hauling logs, grinding stumps and the like. Anyway, I'm just making the point that I'm kind of familiar with the situation. And if you want my opinion... it would be a great gesture on your part to send them the money.
Bear in mind, you're not losing anything... you're just paying what you owed (minus the cost of gutter repair). 150$ will pay one of the employees for the entire day's work. Fact is, if you recognize a moral dilemma, then one exists and in my opinion it would be in your best interest to reconcile it.