Does earning £40-£50K give you a good life over there
compared to the national average ..... you'll live like a King !
However, it all depends if you have expensive tastes and lifestyle ..... in Poland you can eat very cheaply or very expensively; shopping in the designer shops in malls can be as expensive , if not more expensive than in UK !
You can choose to have your kids go to a Polish school with locals, or go privately in one of the many international schools - the Polish state schools are free, some Polish schools are private, but still a lot cheaper than international schools. The most expensive are the international schools where one year may cost in the region of £7000-£8000.
my girlfriend is polish and we're planning to move there in 2 years time
My wife is Polish ... and from Wroclaw. Presently we are in London, but we plan to be living in Poland in 2 years time - our kids are 5yrs and 4 yrs and are already bilingual. Still undecided between Warsaw and Krakow, although Warsaw seems to have the edge.
I have many friends who have already made the move to Polska; be careful not to fall into the 'one-upmanship club', or 'keeping up with the Joneses'. Like in any society people like to compare themselves with their neighbours and to outdo them in materialistic terms. I have seen this happen with expats in Poland, with some spending beyond their means in order to keep up with others.
Good luck with your furure plans :o)