I'd pick teleport but I'm afraid of the splicing consequences.

I'd rather just see inside empty objects. I'm sure I could use this in some circumstances. Being able to "know" if a box is empty or not could be perceived as super natural. There is probably a lot of money in that. Plus, a lot of gambling opportunities in things like that cup game. What defines a container? That could change things.

Controlling any toaster with my mind is ambiguous. I'll assume it only works on toasters with power. So I can only turn them on/off to make toast. I could use this power to destroy countries. Power draw of a toaster isn't too bad, but every toaster being turned on at the same time might damage an energy sector. It would take a while to debug as well.

I like the free gravel.

I think I'd pick free gravel and... Seeing inside empty objects. Seems like the most profitable with the least chance of a monkeys paw.