Ultimately, this is a decision best left up to the autocrat. If 
he or she feels they can still make a profit or break even when offering 
such incentives, then it's fine with us.  It enables those for whom the 
event or feast might have been a financial burden to participate and
food in exchange for labor is a fine medieval tradition. : ) Also, it's 
a good way to lure impoverished college students to events and introduce 
them to the fine art of service.  The seneschal and exchequer should 
keep an eye on this practice; if events (and therefore the barony) begin 
to suffer financially because of it, the practice should be curbed.