I was 30 when I started flight school but on a self sponsored cadetship with a guarantee of a job. That was 4 years ago. I have been flying for a regional for about 3 years now.
For older pilots it is very difficult to get an airline job. The airlines see older pilots as slower to train compared to a young 20 something. This has been said by trainers at the airline.
The jobs front is still bleak. There are plenty of jobs for captains and experienced FOs on type with 1500+ hours on airbus or boeing. Prectiaclly no regionals are hiring with some firing pilots. Expect to start on about 25K GBP at a regional at the most. This is what i started on and am still close to this. The chance of getting into BA is slim so dont go off flight training expecting to go to BA when finished. All easyjet, Ryanair etc pilots will be applying too so you will be up against stiff competition.
Ryanair is pretty much the only game in town for new cadets and expect to pay after flight school close to 40K before you are paid. A guy I know connected to recruitment in Ryanair told me 3 years ago that the unofficcially dont take guys over 30. I was 31 at the time and was told to put 30 on the application.
I traing with some guys 4 years ago who were aged in their late 30s early and mid 40s. All are still trying to get an airline job. The best option in this situation is to become an instructor but this also costs more money, about 7k+.
If you get a job expect to have to move to a different country as if you get Ryanair you will have to move to continental europe and bid to get back to the uk but there will be a lot ahead of you trying to get back also.
At the budget carriers you are a contractor. If you dont fly you dont get paid. If you get sick and cant fly you dont get paid. You will have to pay all your own expenses at some of them. Like your hotel, transport, uniform, meals, training (every 6 months) as well as pay an accountant. So while their pay seems good when these expenses are removed its not that great. You wont be entitled to any social welfare if they dont roster you over the winter either as you are technically self employed.