Why do you want to do this?
If it is so that you can bill the costs to an external client then the product owner will tell you what rate to use. Full stop.
If it is for internal purposes there are two numbers: "kinda basic" and "fully laden". "Kinda basic" is average salary plus benefits (don't waste a second trying to do this for everyone; just get a general average value -- see your project sponsor) or "fully laden" which covers _everything_ including the replacement cost of the kitchen sink. Once again, see your project sponson. Once again, don't calculate the number for everyone, just get a single number and use it for everyone.
And, having said that, you _might_ want to use two or three numbers depending on roles (exec, grunt, other) but it's not worth the effort in most cases if you (the company) haven't been doing it before.
Third parties will, of course, be costed at whatever rate they have contractually agreed to use.