I don't know what this person is talking about, our billing was brain dead simple, it's only got like 20 lines of Stripe Billing code. :-)

But in all seriousness, we looked at Stripe, thought about "aw man is it worth spending the .5% extra" and then spent about 30 seconds thinking about how much time it would take to roll our own, and it was an absolute no brainer.

(replace Stripe with any of the other similar competitors, not trying to be too biased, but stripe is kind of the mind-share default for SaaS startups, aren't they?)