30 years at 5% increases the total interest to 8.4B and drops the payment to $48/mo. Pulling out the $20/mo from their profits gives an extra payment of $28/mo. Though of course with a capital project, trying to figure out how much it “hurts” to make payments has to consider inflation. If we count on 3% inflation (which is conservative) it makes the effective interest rate 2%, and a monthly inflation adjusted payment of $33, which is $13/mo after you pull their $20/mo profit margin out. that seems like a good deal to me honestly. But like you said we dont have a true picture of the cost, loan terms, or their profit.