No. Don't pay. If there's a community large enough to require a moderator, there's another person willing to volunteer in their place.
Well I had a great fortune in finding a good mod. I first set out in when I made my newest site www.fantasy-pc.com . During the first month, I went here frihost.com to ask for mods. In frihost they used fake currency that you could pay users. I used that and at first paid the user Fireboar on there. He joined and we had progress done the first month. The end of the month I paid him his amount (not in real money, fake currency). He said he would do the job for free, since he liked it so much. He helped quite a lot, so I felt he must be a commited user. So since I was amazed and his devotion, I promoted him to Junior Admin, after a few months, he became a real Administrator of the site and still is. He is a skilled developer and programmer, and he contributes a lot. So thats my 2 cents, I think you shouldn't offer real money, but if the persistency comes to that level, then it's really your choice.