I'm considering looking for contractor jobs (in Western Europe). I have the experience of senior developer (Java) so I'm confident of the high quality of value added I can provide to the client. But I'm not sure what hourly rate should I demand? What should I take into account?
Are there publicly available information about hourly rates of programming experts? If the rates are standardized, it would change my problem into simply accepting the rate or not.
Should they be estimated in relation to the employees' wages? For example, they should be 50% higher?
How to calculate the living costs? If I know that the costs of living in given city are 1500€, and in the place I live now they are 1000€, should I add 500€ to the sum calculated in point 2?
Initially I'd probably have to stay in hotel, which would increase the costs of about 500-1000€. On shorter time contracts (up to 3 months) probably I'd stay only in hotel, so should I charge about 1000€ monthly more?
The sums in the question are templates only, to replace by localized costs.