Gil pretty much governs everything, you can either spend two hours farming for 20K if your GOOD at it, or you can find other ways to do it, but one thing is for sure, it takes time, and sometimes a whole lot of it.

You would lvl THF to 18(might take some time, ppl usually dont take THFs without subjobs), lvl WAR your subjob to 15, then lvl the THF to 30 or 37, then lvl your RNG finally. Will take at least one-two months...dunno depends on your style.