I am going to file file for legal separation, about how much should I expect to pay and when, can I have fees charged to spouse?

You do not need to file for a legal separation in CA in order to file for divorce.  There are reasons to file for a legal separation--some of them are religious, or financial.  If you file for a legal separation and then a divorce at a later date--you will pay twice. The fees for a legal separation (or a divorce) vary among attorneys and depend on a number of factors.  If you & your spouse are in agreement over your issues, your fees will be less.  If you cannot agree, you will need to address your issues in court and that is more costly. Most attorneys charge retainer and hourly rates.  You can request that attorney fees be paid by spouse but that doesn't mean that they will be.  Normally that is addressed in court and the judge will make a ruling as to whether the circumstances are such that he would need to pay and has the ability to pay. There are some lawyers, like Legal Action Workshop, who offer a flat fee model which is more cost effective than the hourly system.  We would suggest speaking with a number of attorneys to see which system works best for you.