at first i read your question one way, and then saw it another. the way i see it now, IF both teams are about equal - which i think most people on this board do not find to be the case - then i, personally, would go with jv - again, IF they are truly close to equal - players, coaches, etc.
seems to me, if that were the case, you would have so many more positives to playing for your school. Like you mentioned, cost is one. the "cool" factor of playing for your school (although, some people might not see this - for us, it was), the challenge of playing against bigger, older players (although, like onthefence mentioned, this could also be a negative).