I'm interested to know where you're based, I take it it's not London? A day rate of £150 per day to the customer sounds very low; it's hard to find contract rates that low on the likes of Monster across the UK and typical to see £250-500, so double that for the company hiring out. I've seen rate cards for agencies in advertising charging out developers on projects from £500 to over £1,000 depending on what exactly is being worked on. If £150 a day is too much and costing work anything lower seems unsustainable to run anything more than a lifestyle business for a few select people at the top.

If it's 7pm and the developers are likely to be still there for a while - is that "the norm"? Then you are in effect taking a pay cut already on what sounds like below market rate wages. This sort of practice is toxic. It's ok to work late but when it's expected as part of the job but not without any compensation (can be extra time off, not just money) then this really annoys the hell out of me. Someone higher up is making money out of this. That might be the status quo but I would really consider working on the C.V. and widening out skills and look elsewhere - there's no harm in it.

The guys behind you paid less than median (£21.3k in 2012 according to Wikipedia) and that have been at it for 3 years - from that I get the impression they were fresh out of university and this was the first job? And the highest paid guy at just 10% more, so around £23k, is there no CTO or senior developer? To me it sounds like someone's taking advantage of young, enthusiastic energy here. More so with the "we will be here a while" comment - you should work out what your effective annual salary is based on that; otherwise you can just let it slide and fall into acceptance. If your contact states 9 - 6 the company needs to appreciate the above and beyond work. That's what it is, no matter what others might tell you.

We recently hired for a mid-level developer role at our office in Hoxton and that was around the £40k mark which seems to be around right. As the tech director there I regularly get unsolicited CVs via recruiters and salary ranges requested typically range from the £30k mark up to around £60k.

I don't mean to come off as in anyway 'know it all'y or 'just do x' - I'm genuinely interested in the situation as a fellow UK based dev. Your situation contrasts starkly with my developer friends (based in London, Belfast, Hertfordshire & Leeds) so I'd like to hear more if possible. I often extol the virtue of learning developer skills to younger folk who I interact with and have always painted it as a pretty good way to get a good head-start financially over many other occupations.

When I started out at just above the median I was so thrilled that I was actually getting paid to do what I started out doing in my bedroom as a young kid. After passing the 30 mark I've come to realize it's about what value you can provide to the company, there's no shame in wanting to be out at 6, for one thing realistic timing plans that actually reflect reality are far more useful than ones papered over with hours upon hours of hidden overtime - I'm not saying that hard, late nights are out of the question - I just don't expect it to be treated as the norm' or assumed unless it's also reflected in compensation of _some sort_ (we've in the past traded late nights for conference & flight fees for instance). There's also no shame in taking a look what else is out there and moving if you have to - there is some give and take on your part in progressing. Moving jobs is usually the easiest way to significantly bump your pay grade. It's hard work but can really be worth it in the long run.