I was on the other side of this equation a couple of years ago - co-founder of a London-based tech startup that had just finished an accelerator and raised a £100k round of seed funding (we didn't make it in the end in case you're wondering). Here are a few tips from what we learned.

1) The valuation is completely and utterly meaningless at this stage of the company. Unless the company is already generating a profit, it's currently worth exactly $0. So forget about the valuation when making this decision.

In addition, as you mentioned in your description, this valuation is literally a completely random number they pulled out of thin air.

Just for your reference, London-based startups that raise a seed round after having completed an accelerator are typically valued in the region of £1m. They would have to be quite exceptional to be valued at $3-4m (and maybe they are - up to you to find out).

2) I'm no expert on what's a reasonably equity share for a first employee. 2% sounds OK. But in any case, those 2% are worth exactly nothing right now. And at the stage they're at, their chances of success are close to non-existant (just like every other startup at this stage). So those 2% will most likely never be worth anything. Take those 2% as the icing on the cake, not as a main decision factor.

3) The £1.4k / month salary figure is a bit odd. Salaries in the UK are usually expressed as a gross annual figure, not as a monthly figure (or at least that how I've always seen them expressed). So do they mean a salary of £16.8k gross or £20.3k gross?

In any case, since it's a remote position, you're the only one who knows whether this is a reasonable offer or not. In the UK, that would be far, far too low for an intermediate-senior level developer. Even in the parts of the UK that have the lowest salaries (e.g. Northern Ireland), £17k would be borderline taking the piss for a graduate-level position, let alone senior.

But then again, only you knows what you could expect to earn where you live.

4) What accelerator did they go through? The purpose of an accelerator is mainly to "get the badge", i.e. get the credibility associated with the accelerator and get accepted into the "inner circle" of entrepreneurs and investors in the region. This is what makes a huge difference to the startup's ability to raise future funding and get the right introductions.

As a result, the only accelerators that are worth going through and provide real value are the top-ones, namely: YC, 500 Startups and TechStars. So are they part of the inner circle or did they just go through a small, fairly unknown local accelerator?

5) Since they haven't yet raised seed round, they probably don't yet have a formal board of directors. So failing this, who are their "official" advisors? Do they have any high-profile, successful entrepreneur helping them out (i.e. someone who's been there before)? Ask to have a chat with one of them. If their advisors are really willing to help them and are not just advisors on paper, they'll be very happy to have a chat with a prospective employee #1. Be blunt with them - ask them what they think of the company, of the founders and of their future prospects.

6) Finally, I realise that the above might come across as quite negative but this isn't my intention. There's plenty of upside with being employee #1 at a tech startup, even when the salary is questionable.

- It's common in early stage startups to be very relaxed and flexible when it comes to working hours, days off, etc. especially given the very low salary they're offering. Have a honest chat with them about this.

- If you're genuinely interested in startups, there's not better way to learn the ropes than to be employee #1 at a tech startups. You'll learn almost as much as you would being a founder and you'll be paid for it!

- Although your 2% will probably never be worth anything, there is a good chance that the company will grow enough to see its team reach a sizeable size. As employee #1, you'll be first in line to move up the chain of command and to be given a lot of responsibilities. You'll probably learn more in two years in a startup than you would have in 10 years at a large corporation. That certainly won't hurt your CV.

All of the above however is conditional on the founders being completely open and honest with you and on you having an excellent relationship with them. So up to you to see whether you and the founders "clicked" and whether they're going to be open with you or keep you at arm's length.