The terms are fine. 1.38 7.5 months for $20,000 is great for a Merchant grossing $30k-$75k. For someone doing $500,000 in sales.... I don't know.

On the other hand if his margins are low and/or he is seeking a similar amount, it is fine, depends on your skills as a Salesperson, as others have said.

Is he depositing $500,000? Does his P&L/balance sheet reflect that. It's like 1 day worth of sales..... I don't know all the facts, but I don't think it's your business model or the factor, just the amount offered is a potential problem.