The price to get into the Con is always the same at the door, though if you only pay for a one day ticket it is less than a full weekend ticket. There is no price benefit for Con tickets if you stay in a room. It's just more convenient for people to stay at the hotel if they don't live in the area, or know that they'll be pulling so many shifts they won't be able to get home even if they do live close by.
If you are thirteen or under (Is it 13? I think it's 13.) you MUST have a parent/guardian with you to get into the Con. Sorry about that, but it's more for your safety and us not getting sued than anything. (We figure if the parent comes with you, and is offended by anything to the point they don't want you there, they can drag you home and not blame us because they did drag you out of there.)
There is a curfew if you are under the age of 18, and you will be required to be off the Con grounds (Not the hotel, but the Con viewing rooms or gaming rooms and etc) by midnight (I need to double check that. ^.^; ) as per Portland city law. Or Kumori Con rules. One of the two.
But other than that it's really fun, and you really should come! ^.^