It's difficult to put a number on this, as it really depends on the route you take. If you go integrated, as an example, the main school in Scandinavia will do zero to CPL for roughly £65k plus incidentals. An IR with them adds around £35k, so approx £100k all in.
If you start out with a clear, multi-year plan (and stick to it), you can get it done for less. I know, I've done it! I started with a 4 year plan which became a 5ish year plan, and prices were definately lower when I started. My route was PPL, hour building, ATPL ground, CPL, IR. All flight training was in minimum or near-minimum hours. I was very lucky in my first career, so with some planning, I finished with no debt. I worked very hard to get the hour-building costs down, and with some luck and a lot of running around, and some help from others, I had some amazing experiences and got some very cheap hours.
I estimate my total costs at between £85k and £90k. I haven't added up the final bill yet - I'd prefer not to know - but it's definately 'could have bought a house' money. There are ways to reduce the costs, if you're prepared to take the initiative and do the legwork. If I was starting today, I guess £95k - £100k would be a reasonable guess.