Sounds like the same scam as paying SBD for upvotes, the only difference is that when you get a resteem, you know who your "wider audience" might be as opposed to simply getting "paid by an upvote".

Granted, being paid by an upvote is "guaranteed money" while being resteemed is simply the opportunity for someone new to provide you with an upvote.

Your 20% power upvote example actually shows how the resteem could be more valuable. If you were unaware of an account previously and stumbled upon them because of a resteem of one of those who you follow, the 20% upvote would be worth more than a bot where you pay SBD for the upvote of that single bot.

I think all of these methods are silly ways to "game the system" and completely go against the core of Steemit. Too many accounts are on here trying to "make a quick buck", and the whales who have lots of steem power are encouraging it. It's really a shame.