Well first of all I,m assuming there is no chance of a str8 or a flush on the Board ?? Then the only threat is a higher set. You want to get as much $$ from the hand as you think you can. Not many details here. But if 1 player raised I assume the limpers will all fold. So you may as well re-raise the raiser for as much as you think you can get him to call. $400 sounds like he,s pot committed in a $5 game so Push him ALL IN.