When you start getting into raiding, potions start to become more of a fact of life. As your guild advances through the raids, regular flasking and potion chugging is going to start to become more of a standard part of your play experience. It'll be a constant expense that you'll have to farm gold for, adding to the amount of time that you'll need to spend to keep your game at its best. Many guilds actually require you to be chugging potions and flasked constantly, so that's something else to take into account when you're deciding just how hardcore you want to get.

One thing that can help to keep your costs down is either to level an alternative character with alchemy and herbalism, or to buy the raw ingredients and ask a friendly guild alchemist to brew your potions for you. This can result in savings of hundreds of gold a week if you're in a more active guild with a need to chug lots of elixirs, flasks and restorative potions.

Make sure that you're doing a cost analysis relative to the current prices on the auction house. Buy supplies on Monday-Wednesday, as most guilds raid starting on Thursdays going until the weekend. If you're selling supplies, sell on the weekends to take advantage of the higher demand and potential prices. If you're up to the Serpentshrine/Tempest Keep raid lines, you'll be able to take advantage of some of the tokens dropped there to get free flasks that will help you absorb some of your costs.