I have not found making money in Skyrim to be a problem in the slightest. I've got about 80 hours worth of playtime on each of my 4 playthroughs and I have an average of 500,000 gold on each one of them. If you want to earn money quickly, I'd highly recommend completing the Thieve's Guild and finishing the quest "No Stone Unturned". The fences have about 4000 a pop for selling purposes and with Prowler's Profit, you will find roughly 2-4 gems in every single chest, urn, or any other container short of barrels and sacks that is not empty. Everytime I unlock this perk, I earn more money than I actually know what to do with.
EDIT: By the way, that is 500,000 gold after buying every available house and upgrade possible in the game.