If you want to know what $ upvote is now onyour desired SP, you can check it on
https://steemnow.com/upvotecalc.html
If you want to see anyone's voting power as well as upvote in $, you can check it by entering their steemit user name on
https://steemnow.com/
Other than this you can see all bots which are selling their votes to you on
https://steembottracker.com
If you want to lease SP, you can visit
https://minnowbooster.net/lease
For selling your upvote if you have enough SP, visit
https://smartsteem.com
https://minnowbooster.net