If you're looking for more money, you're better of running dungeons and cleaning them out - i.e., selling everything that drops. I usually leave Riverwood to go to Whiterun with a new character with about 7000-9000 gold, sometimes more.
My level 43 has 196,000 gold, and the other 3 each somewhere between 60,000 - 100,00.
I don't even sell stuff anymore. It was OK for the first one, learning the game and seeing how much money was to be made, but with my last 3 characters I get enough to buy some houses, and that's it.
PS: The amount you found is normal. There are one or two dungeons where there's between 75-150 gold in each urn, and 75-100 on dead bodies, but they're very rare.