If your a technical founder and building the product yourself I don't see why you couldn't spend a couple thousand to do it right, cutting corner in design is one of the top mistakes technical founders make. Spend a week consulting and it will cover the design and more.
To your customers, there is no difference between your "design" and your "product". If I had to choose between scrimping on design and scrimping on features, I would choose the latter hands down.
While I definitely agree that a couple thousand isn't that much, it's still more expensive than a lot of "night and weekend" entrepreneurs can afford right away.
