As far as I'm aware, if you go for Orka Cloud, you only pay for the physical Mac, not the VMs. I've no idea about the hobbiest market, I've only used MacStadium for a large company. I didn't personally make the purchase but that's the information that has been relayed to me.
To the hobbiest market, yes. But large companies, at which this seem to be aimed, work with names they know, not names they don't.
The company I work for would pay more to use Amazon than MacStadium for equivalent products. That's just how corporate bureaucracy works. It shouldn't, but it almost always does.