It’s highly depends on the country you’re working in, and under which status : operator’s permanent contract, vendor’s permanent contract, consultant, freelance…
For freelance, expect between 300USD and 700USD / day, depending on country, experience, project, competency…
GSM optimisation in UK or US ? you can check http://www.jobserve.com, to give you a rough idea of what’s going on. It is mostly middle east and african countries that are looking for optimizers…
2 yrs experience is not much, unless you have been exposed to various operators and various jobs…