As a RDM, it makes me sad to see what lengths other RDM (and all staple jobs) can go to and get away with. I pride myself on having the best equip I can at any given time (double astrals, light, ice, dark staves, rk belt, morions, yadda), and I take it as a personal insult if a player in a certain job, especially a job I've grown to love, has the "I can do whatever I want and parties will still invite me," attitude.
Yeah, Dispel is expensive at a low level. But you know what? Ask a friend if you can borrow some mining gear. Go to Yughott Grotto or Zeruhn Mines with some pickaxes. I guarantee you'll make the money you need in a day, two days. Every time I've gone mining, I've come out of those two places with easily 40k worth of ores, and sometimes 100k+ from mining in Ifrit's Cauldron. Mining is one of the easiest ways to earn money even with the underhanded tactics people use. There's no excuse not to have essential spells like Dispel, Refresh, Haste. Phalanx I can see not having, because after all.. you should really only be using it when you're soloing, so only you will feel the repercussions of it.
*shrug*