Here in Colorado there is no benefit for legal separation vs. divorce. They serve the same purpose. My divorced friends here also tell me that their attorneys suggested just filing for D when the time is right - they require the same documents and classes. We used to live in California, where the laws are very, very different.
When I went for an initial review with an attorney, he recommended a mediator who was recognized in family court. He suggested to us that if we wanted to save money, to contact him on our own. So what my XH and I did for the 2 years we were separated was to draft a legal Memorandum of Understanding. We specified the date of separation, ironed out parenting time, spousal and child support and things became locked in as valid to protect ourselves until we either reconciled or filed for D. This MOU was a legally binding document, and could have been used as a basis in court if either one of us were to violate the agreements. I felt it was important because I wanted my kids to be protected. And my interests in a 12 year marriage at the time.
That MOU would also be the ground zero point for any debts incurred after the date of separation. It's a whole lot cheaper and you don't have to show up to parenting class or meet with the GAL and have deadlines to provide the necessary documentation. By the time my XH realized that he wasn't going to come home, we were able to convert the MOU into court orders. We changed some of them, but kept most of it.
"There are only 2 ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."
