I'm running about 10k now. It's usually lower, but Randimar's has had little to interest me lately, plus I read the What is the shortest method to get most gold pieces (gp) thread and improved my farming method.
Gold doesn't accumulate that fast. I honestly think they should rotate Randimar's a bit faster. Unless you're buying gold or spending hours and hours grinding for gold (in which case, good for you) you might be able to buy a legendary or a few epics every month. It's kind of annoying just sitting there stockpiling the gold and occasionally buying a fringe rare that might conceivably be useful just because there's nothing else worth buying.
I've never had more than 540 or so. I farm all of the high-level quests daily, complete them with ease, and then MP for the first two or three chests, depending upon how much time I have, and I never have anywhere even remotely close to enough gold. Never been able to spend much on Randimar's at all.
what stuff should I sell and what do I keep? the first time I played the campaign I sold every thing that had drawbacks and had to get my game reset as I couldn't play any of the quests.
Some drawback cards are useful, but that only becomes clear later in the game and not just for the drawback quests. You could keep the maximum amount of usable cards, like 3 helmets, 6 staffs and so on. That is the safest way to handle equipment you are not sure you might need someday.
A little tired of being the poor person in these threads, glad to see that I have at least a little company this time. I'm currently sitting at eight gold, all treasures sold. I've been playing since launch and I play most every day (some exceptions) but I'm on dial-up right now so I usually only do one adventure per day. I've done most of the quests, excepting the 1 hp ones, and in that time I've gotten five legendaries including the Hand of Melvelous and I think three or possibly four epic treasures. No legendary treasures. I've never purchased a legendary or ever had anywhere close to enough money to do so.