Are you asking a theoretical question, or a practical one? If you're asking for yourself, you should probably see a fertility specialist immediately, as they might want to harvest eggs now, for use later, if that's an option. If you're speaking theoretically, then perhaps you should be asking about infertility treatments, rather than surrogacy, as most infertility treatments don't involve in-vitro fertilization, let alone surrogacy.
A round of in vitro fertilization can cost about $10,000 to $12,000. I think getting donor eggs can add about 15-20k to that cost. Many people go through several rounds of IVF before having success or giving up, so they might end up spending up to 50k, without egg donors.
Google just told me that a round of IVF plus egg donor plus surrogacy fees plus legal fees will total about 90k.
One large medical group that I'm familiar with provides medical insurance which covers much of the cost of infertility treatments up to a certain amount. (25k , I believe ) I don't know if they cover surrogacy expenses, but I suspect that they might, although I don't know under what circumstances that would be covered. However, the average US income is about $59,000, and most physicians will earn above 200,000, so that should leave you with plenty of money to put towards fertility expenses. Just remember that will be able to afford almost anything, but not everything, so if you want to afford the fertility treatments, you should avoid buying an expensive house, a fancy car, or exotic vacations.