It should be 25k SP for giving 5$ upvote

For borrowing this SP I need to pay 640Steems (which I should get from some there) means 160 Steems a week for posting junk 10 times a day and get as a result 350$ devided on 0.5 (Steem rate), as a result I'll get 240Steems.

I more believe in natural growth. None would comment on junk posts and none would upvote these sort of posts. I would have a risk to lost existed followers and upvoters.