What costs are you referring to? Taxes on your profit? There is a county transfer tax on every sale that usually the seller pays. In San Diego County, it is $1.10 per thousand. (For example, a $300,000 home would have a county transfer tax of $330.00). If you want to talk numbers and need me to run a seller net sheet for you, which would give you a good estimate of your profit when selling, feel free to contact me directly- I would be happy to assist.
I'm not sure exactly what State costs you're thinking about. If you own the home as your primary residence and sell it then it will be the same state tax situation as the Federal Taxes. There's no tax owed for an individual who has $250000 or less gain on a principal residence nor for a couple with a gain of $500000. Naturally, you should consult a tax professional to confirm this information as I am not a tax expert. Here is the CA Franchise Tax Board link to the explanation of what must be withheld if it's not a principal residence http://www.ftb.ca.gov/forms/misc/1016.pdf
If I've misunderstood the nature of your question and you're referring to another type of cost, please expand on the question a bit more.