condo unit

I am planning to buy a condo in California City. I have a few questions about condos and listing square footage. A friend of mine recommend to me a real estate firm. I saw some good condos in their brochures. I am looking to buy a condo, which is listed at $145,900 with the square footage of 1262. It is a second floor unit. I like the place. I like it on the picture. When I call the firm, they said that there are no other condos with that square footage, so I went in and measured the square footage myself. I find out that they are including the square footage of the deck in the listing. I was under the impression that only livable space can be included. Can this square footage be used in the purchase or (psf?) price? Do you think it is legal? Should I refuse the condo?