I’ve used similar services to this in the past; not because I couldn’t afford something up front - but because I wanted to amortise the purchase across a pretty short (8 week) period.

Why not just use a credit card? I did. As a semi-regular user of the service, it was set up in such a way that it would bill the first 25% of my purchase after 2 weeks, and again every 2 weeks after that.

So not only was I getting an additional interest-free time stacking the 2 week period with my CC’s billing cycle; but I was earning loyalty/rewards points with both programs simultaneously.