In Skyrim, I bought a 'Breezehome' in Whiterun and it only costed me 5000 gold (+1800 gold for furnishing every room). I was only able to buy a house after completing the Jaarl's requests and becoming a Thane of Whiterun.
You will receive the Skyrim 'Citizen' achievement, worth 10 points, on Steam.
Here are more expensive homes you can own in Skyrim:
Check this video on How to get a House, Breezehome in Whiterun!