I have heard of a few pilots getting jobs in their mid/late thirties but, as you'll no doubt pick up from simliar threads on this subject, your age will be taken into account when two equally suitable applicants are being considered. Completing your training at this stage does put you into competition with ex miltary pilots of the same age with loads of hours, but when times are good they seem to get snapped up by the big boys. I know of a guy in his mid-forties recently hired by a cargo operator, though he did have 1000+ hours, and another 38 year old low hours guy get a job on a t/prop.
Being in a similar age-group myself and halfway to a f/ATPL, I've been concerned about this issue as well. I've attended the last couple of BALPA employment conferences to try and gauge opinion direct from the airlines. The general theme from regional/low cost/cargo operators was that while they had min requirements on hours/age/experience etc. the bottom line was that if they liked you, you'd have a chance. One said they actively looked for applicants who'd 'grown up a bit' and got some life experience, while another regional airline said they wouldn't consider anyone who'd hit 40 and only had 250 hrs.
Like applying for any job you're in competition with others and given apparent over supply of trained pilots in the UK, it seems a you need a type rating + experience at the moment to get a sniff of a job, never mind being the 'right' age. People better qualified than me are of the opinion that the market will eventually pick up, but who knows when? When that does happen airlines will be forced to lower their sightss on age & experience but will still look for people who they feel they can fly with and get through a type rating, cost effectively.
But, if you're like many people I know (myself included), you probably won't be able to resist the urge to start training no matter how bad the prospects appear!
Best advice I could give would be to speak to as many people as possible in the industry and come to your own conclusions.
SJ