The other side of that is you may not finish your PPL due to financial constraints in the UK. I had posted on a previous thread re: a freind who had just finished a PPL at a Northern school which took him a year flying weekends and the odd day on the week, mainly due to weather and lack of instructor.
In the end he clocked up 90hours (which is easy to do if you have to revisit lessons due to a week or two off due to weather, etc) and he worked out his PPL cost him about £16,000.
If you can afford a month off work then I would go the US route for your PPL and then decide what you want to do from there. At the end of the day its a licence to learn and you will be constantly building on your skills once you return.
If you cant get the time off then go the UK weekend route which is obviously much easier to fit in around your work calender.
If you go to the US the things to budget for are the course, flight test, exams (although strongly reccommend you do these in the UK and get them out of the way!), accomdation and food and the odd beer
Whenever I have been most hotels have run a free bus service so not needed car hire and of course once you pass you wont need car hire as you can fly everywhere sightseeing
J