This post gives a more detailed break down of the specialists 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 58 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 job and the highest pay is about 18% but that ranges from 8% to 41%. You can see a wide spread in starting pay which is most likely due to the fact that this category covers so many possible jobs.