I don't know the school so can't comment on them. All I want to say is that I did go to another country (outside the UK) to do my training to get a better price, but even with that I would be quite wary of a price being TOO good. Research required.
To give you a very basic idea of how things work (doesn't always work exactly this way but it's rough), this is what you will do in training:
PPL
Night Rating
Hour building
ATPL Theory
CPL
Multi Engine IR
(MCC)
Not all flight schools include / can do an MCC, mine didn't so I did it elsewhere. Certain elements above can be done together and others need to be done on there own, whether through legislation (if you don't have the requirements to do another part of the course yet) or through it needing to be focused on more (I know some school that do the CPL and IR together and others that advise against it).
This will leave you with a CPL and ATPL theory completed, commonly referred to as a Frozen ATPL (which is NOT a licence itself, just common used terminology).
Once you get 1500 hours including a certain amount of night hours and other things, you can do a test for your ATPL (or to 'unfreeze' the fATPL).
I would not call this time hour building as such, and would not say that you build to 1500h to "become a captain". It depends on what you are flying of course but as most people will be looking towards flying jets in airlines, you are probably looking at closer to 3000h in most airlines before they would start considering you for an upgrade, and in bigger airlines that use a seniority system (longer in the company gets you more 'benefits' or options so to speak) then you might be looking at over 10 years and have many thousands of hours (perhaps more than 10000h) before being upgraded.