You can either be a free member of Club Penguin or you can be a paying member. If you are a paying member, you can upgrade you house to different shapes, sizes or styles, buy clothing, but furniture for your house and buy pets for your penguin which are called 'Puffles'. Another feature is that when another room gets added to Club Penguin, there is always a member party and non-members have to wait a week until you can see it.
The prices are:
1 Month: $595
6 Months: $2995
1 Year: $5795