I'm not a lawyer, but there are documented court cases in Finland where "two entities entered a contractual agreement over an agreed price", and then later the court determined that the price was outrageous and therefore it was actually fraud. For example, a door-to-door salesman selling house renovations to elderly people for 10x prices. Now, perhaps this is not fraud in the jurisdiction where you live, but it is definitely fraud in Finland.
> selling house renovations to elderly people for 10x prices
is illegal if the targets were elderly (or disabled), but not if you are just regular Joe and definitively not to business. In fact that's how politicians usually "help" their friends here, so laws are quite muddy probably on purpose
You literally can set arbitrary price to your time and at worst there won't be anyone willing to pay it.
This checks as long you give your rate/price upfront. This would be a scam if you DO the work and THEN charge non-market rate/price.
If you go for a quote for a simple android app (iPhone is not that popular here) you are quite likely to get more than 10x difference in quotes from various studios.