As WWW says, most of us, prior to these schemes flogged around as instructors. With luck you would then progress to piston or light turbines flying any kind of work available all for crap money, sometimes for years. With a little more luck if you survived that bit, you would eventually land yourself a decent job having served your apprenticeship. £2000 to £3000 a month for being tucked up in a cosy warm Airbus with a (sometimes) experienced captain; you don't know how lucky you are. Wakey, wakey.
However, if BALPA insisted on equality of pay and contract for f/o's as achieved by our European neighbours they might be worth £10/month. Instead they decided that they were unable to represent their interests because they were not easyjet employees. Couldn't possibly get hands dirty or spend any cash on such a tricky situation, noo.