$120/month is a drop in the bucket. You need to look at the opportunity cost. His time is worth over $100/hour and better spent on other things (features, marketing, whatever..)
If he gets a ton of customers, he'll need to expand anyway and will waste even more time setting things back up.
Well, you know, I'd like to think my problem is sales/marketing and not product.
Maybe you know it, but reading your comments it looks like you are treating sales/marketing as an afterthought.
For running a successful business, I think you should try to always have the others in mind when you work on one, because that’s how you can find product/market fit (otherwise it’s mostly luck, and/or you had perfect hindsight of your market).
Better to save money and expand if and when a paying customer shows up.