Lot of gold is more than 2.000 gold with the epicmout skill 150 already bought and that is by far not my case YET

but now i see what you mean they have a ban system...
Well i created a second account for more bankchars. I didn't want to spend gold on bags. For me every silver counts. Hope this didn't triggered the ban system, I sent a lot of items and never sent more than 1 or 2 gold to my bankchars due to the fee you have to pay for an auction.
I made a lot of gold with pvp twink items I waited till there were no items with the same name an put them in with an huge price some times they sold some they didn't. Also bought some items to have the "monopoly" (monopoly is a google translation, when you are the only supplier on the market) and put them with an huge profit margin in the auction house. Often they didn't sell but when they did it was big money in my bank.
It was a bit from everything some +fire spelldmg (fiery wrath) or +frost spelldmg items for mages, +shadow spelldmg sells really good, some blue items and finally shoulders that are really uncommon at lower levels.