2 years is a different kettle of fish to 3 months.
I understand you charging 3x if its that long. My kids and dog make an awful mess of some of our windows.
Obviously the same price for insides would only count for the ones you cleaned from the outside. Partitions and internal windows would be an extra unless you wanted to secure a job.
Dave has a really good point as Dean Taberner has also said.
The fact that your there already does make it easyer when you think about it. Its a case of packing up the wfp gear and getting your trad kit out.
Thinking about it logically, if you were to move on to another job you would have the time of getting there, unpacking wfp kit, fuel costs and securing the work to do on the same day. Might take a little longer, but if you add up the time and costs of moving on to another job it makes sense
I for one always thought it would be a hassle and therefore I would have charged more than the same.