Monofire or Fire/X is actually not a money deck at all IN COMPARISON TO things like Earth...
you could easily get away with running 3x Backstab, 3x TP4 jutsu that also costs 1 fire and etc and run a cheap rush deck... you don't need dragon flames. Yes, it's competitive -- is it tier 1? no. but it can go brainless and just win off luck and such.
Other than that... monowind puppets?? pretty cheap... Void is also cheap - you could buy a starter and run it at the event and you'd probably win at least two rounds lol..