So I'm on the fourth session for my first EotE campaign, and I have a lot of cool things planned for later, some of which will require the expenditure of credits by the party. My question is, "Do you have any tips for doling out resources to the party, and finding a balance between keeping them dirt poor but at the same time keeping them from being uber rich"

Reward well but charge accordingly. Make them pay to repair ship damage. I've taken to randomly rolling on Despairs with weapons between Out of Ammo or damaged, and they need to pay to fix or replace damaged weapons. I don't feel the need to have them pay for groceries, but if they want to upgrade the ship, that requires a repair bay and heavy equipment for swapping out parts and such. Use your imagination and think about actual costs for ship upkeep and fuel. etc.

Also, don't restrict your loss/damage to weapons, all kinds of equipment can be lost or damaged. I'm also a fan of punctuated rewards - you have an adventure that provides money, than one that might just pay down a little obligation, then one where just surviving is success. (So in effect, the initial money has to last three adventures) Bribes, information, docking fees, abandoned material and more can all take money away.

Also, if you're just starting (and in particular if you don't have a lot of legitimate business downtime) establish the pattern that the group bank account dwindles between adventures to represent survival expenses and standard of living.

I'm an advocate of allowing the party to build up a cushion. Have the first few sessions reward the players with a good bit of money and then slowly bleed it off of them. Nothing prompts players to action like having some money to spend. They'll want to go shopping, find rare items, etc. This leads to travel, which leads to adventures, which lead to entanglement with other organizations. Pretty soon, the party will be busy in the game and the money will be a secondary concern.

As long as they have -opportunities- for profit, they should be able to adjust their own income to match their wants and needs. Just make sure to throw in some moral decisions between getting paid and doing the right thing from time to time to figure out where they fit in the universe.

If you give them money between 7 to 12k at a time, they'll have enough to pay for living expenses for a few adventures, an upgrade or two, and a savings fund for capital expenses or emergencies. Of course, if they don't handle those funds well, then that's on them. Make sure -their- decisions matter.