Money should not be an issue if you have more than 3 toons, if you set it up right. I ran my druid, lock and mage from 30 to 70, and along the way ONLY bought bankslots, training, and profession training.

Make sure you have all 3 gathering professions. Even if you don't need the mats, because you can bank them and power-level a toon later, or sell them. Herbs are good money now from inscription.

Make your toons make their own gear. Leather for shaman, tailor for clothies, etc. You should not be buying gear, ever.

Loot everything, and sell it. AH for the rare, vendors for everything else.

I skipped training riding skill. I can grind that cash a LOT easier at 70, than at 60. I don't care if they get their epic flying mounts, or even flying mounts, but they will get the fast mounts. This is up to you, but it's a HUGE money sink, and if you're struggling to pay for training, then it's something you should forget for now.

Run instances, for experience *and* profit. Mid-range shards, and some essenses, are big money now. Eternal essenses are essential for leveling enchanting, but too few people are running instances where the gear that DEs to them, so they're rare. Greater Eternals average 17-20g each on my server, maybe even more, now - and you need a LOT of them to level enchanting.

Get a guild bank, and set it so your toons repair from guild funds. Set a money amount, like 10-20 gold, and everything over that gets deposited. Set it so only one character can get more than 25g from the bank at any time. My guild bank was at 4k when my 3 hit 70, with no additional funds from my 70 rogue. The money adds up fast. The only thing you should be buying is reagents.

This should keep you afloat, you should have plenty for training. When you need more, grind some instances. I managed to buy 2 bank slots and level all 3 toons, and they were never broke, I maintained a 1500g balance at all times from 30-70, and once I got to 70, the money started pouring in, and I was able to max out professions and use the banked mats (primals, cloth, leather, etc...) to get all the goodies, like a complete Frozen Shadoweave set for my lock, without buying anything from the AH. I leveled the mage to 365 inscription from banked herbs, and the druid needs to farm a little more clefthide to get a complete clefthoof set. My lock DE'd every drop I could'nt use, and banked the mats.

I never buy health or mana pots, I don't need them. I did'nt bother with first aid, and I have a bank tab of cooking mats to level one or two of them, for the cooking dailies. I don't fish. I have stacks of mana and health pots from drops that i don't need. I have gone through stacks of netherweave and runecloth, and it keeps pouring in. I have stacks and stacks and stacks of leather banked- I have a small fortune in turtle scales alone! I have BOE blues socked away, and more shards and powder and rep mats and gems than I know what to do with. I stopped banking scrolls and recipes and designs, because they're common, and they were taking over a full bank slot. Sell 'em! It may be only 1 gold, but it adds up.

Get the bank. Buy the slots, get a tailor, make bags, make sure every toon has max bag slots and bank slots, and start socking stuff away, or selling it. Money is *easy*, if you don't buy anything - and you should'nt need to, the power of numbers means you don't have to max your gear out leveling, you can save that for 70, or now, 80. If you have 5 toons, you should be completely self-sufficient, and the only time you go to the AH is to sell stuff.

Just my advice, worth what you paid.