@Century - yes, that's one way of going about it. Another, for which there is precedent here at Logotournament, is to make special arrangements with LT admin to the effect that you wish to raise the prize offering with the stipulation that it is to be divided up in a specified way between a number of winning designs (eg. $400 1st place, $300 2nd place, $200 3rd place - or whatever you think will garner best results). Contact link below...
https://logotournament.com/help/contactus