I would like to look into that option.. 

There's a site called 'Songbay', but I couldn't recommend or vouch for it.

iTunes and Amazon sell songs as does CD Baby and probably a bunch of others....
 
Google search for the lyrics. Unless the song is brand new, the lyrics are on multiple websites at no cost. Copy to a document file for your own use.

I'm afraid I don't quite get your question - what is it specifically you are looking to buy?
 
-Tom

I'm assuming you meant buy original lyrics? So you write the music and buy some lyrics to with said written music?
 
If so, then I can't help. But instead of paying, have you thought about looking for collaborations, here, homerecording, joinmyband? Free and both parties win. Saves some money and stops you ending up with a set of lyrics that you may end up replacing with your own but still being out of pocket.
 
If I've got the wrong end of the stick, then I'll step away and let others advise