I don’t mean to be rude either, but you shouldn’t assume that someone doesn’t know what they are talking about or understand.
From professional experience I can speak pretty confidently on the subject that staffing opex is almost universally going to supersede cloud opex.
EDIT: I noticed that I was being a bit unclear when saying fixed. What I mean by fixed in this context is that you need to develop the whole e-commerce infrastructure regardless of if you have 1 game or 1000 games - a simplification as you do need to take care to scale well when growing, but it is good enough for the purposes of demonstration. The more games sharing the same e-commerce infrastructure, the less the e-commerce infrastructure costs on a per-transaction basis.