Buying likes won't get you more work from Facebook via your FB account. Fact!
Buying likes is likely to penalise you in the eyes of Google if your FB site is linked to your main website. Google will likely know you've bought likes because of the manner in which the likes are accrued and from who. So don't buy likes!
You're not likely to get any sort of decent work via FB, you might get some I suppose but nothing to write home about. Direct your efforts elsewhere, to your website perhaps and if you insist to Google Adwords if you want to go down the Internet to secure work.
There was a fella used to come on here a few years back spouting off how FB was the next big thing in advertising. He reckoned he was a webmaster, his own site is an abomination, but seems we're still waiting for his predictions to still come to fruition.