£42k after 3 years? Where are you working - London? That makes rather a large difference, as I'd be shocked if someone was getting that after 3 years for web dev here in Manchester.
But yes, in London... people start North of £30k if they're able to demonstrate that they've shipped something.
There are people who make it to SF from here but it's mostly to the big corps. The rest of us will hang around Asia earning relative peanuts while possibly hoping for a side project to take off. Given the poor wages here, it only makes sense to try to get a business going.
Come work in Singapore anyway, you deserve better.
I know one guy who contracts with a US-based company while staying in Asia, exploiting the gap between salary and living cost seems like a pretty smart play.
Question for the Londoners around here: what is the salary range like? I gather that NYC and London living costs are similar (with London supposedly edging out NYC slightly), but around here $120K is common (80K GBP), and in finance frequently runs higher than that. 40K GBP sounds strangely low, but I may lack context.
p.s. all numbers are pre-bonus, but for junior devs they're near-negligible in both companies anyway.
p.p.s both jobs are enterprise java.
Net Income: £2750/month Major Expense: ~£1750/month
Add £100/month more expenses for public transport to work (since in London it's not very common to live within walking distance of work).
Probably a fair comparison might want to factor in university education cost. In the UK undergraduate fees are capped at £9,000/year. So a simplified sum: a 3-year undergraduate costs £27,000; spread over 10 years that's £225/month.
I'd expect someone with 3 years web dev experience to be anywhere from mid-20's to mid-30's outside of London, and a cursory search for Suffolk that appears to be about right.