Well, normally an appartment will require gold (or more), personal status points and often also belonging to a guild of a certain level. Guild status you contributed shouldn't matter. It could be that you try to purchase an appartment with a character that is below lvl 10, but judging from the fact you have the 14g and 557 guild status, I think you're above lvl 10. I think the lvl 10 you see on the sell screen is the level of guild you have to be in before you can buy it.
It is possible that you are trying to buy an appartment that requires more than the amount of personal status that you have at the moment. The fastest way to gain personal status is to sell all the items you find at the appropriate vendor (the status items I mean, like relics and the likes), do guild writs and in particular do heritage quests. The latter are the hugest boost at once, however most do take some time to finish.