Everyone will get interested for that pay rate. But before watching the offer you should check the site and ask for escrow. He/she might not pay after 29 days? possible isn't it? So why not try to deal with escrow.
Only do the work if he /she has agreed to use escrow otherwise you will be only doing free work.
50% ? Will he give 50% after 29 days ? ( 100% sure? ) . Risk is there so I am just pointing it out. Users out here should know what is right. We have seen many scam accusations which happens without escrow and with the rank status that users posted up here in this thread , I assume that most of you guys already know the consequences of going without escrow.
You are right, he need to escrow 100% funds for the task as working as a moderator is not an easy task for that he will have to come full time for forum and will have to read each and every post of the members in order to maintain the quality of the forum etc.