This post gives a more detailed break down of conservation positions (both commercial archaeology and SMR/CRM) in the Jobs in British Archaeology series. These are your GIS techs., osteologist, surveyors, etc.
You can see the methodology here on how these numbers were collected from job postings. In total 40 job postings are represented here.
Lowest pay offered–
Highest pay offered–
Here is a distribution of starting pay (lowest pay) to give you a better idea of what pay is like for this position-
On average the difference between the lowest pay offered for a position and the highest pay is about 15%. Look at the distribution of pay above and add about 15% to estimate what the high pay is for this sort of position. It is pretty sad that the majority of jobs pay so little for conservation positions.