Thoughts on valuing my company?

I run a complex ecommerce health service in the UK. I’m running at £150k revenue a year. Drops out £75k profit, although that includes my salary.I just secured a deal that should add £100k profit p.a. Great! And then they surprised me by asking instead of partnering would I sell all or part of the business to them, to expand operations into the US etc, which I wasn’t expecting.I don’t think the company is yet worth enough to do so but curious as to how this might be valued;3 x earnings = £225k. But not if you take my salary out. And I’ve been reinvesting profits to avoid corporation tax. So net profit is deliberately zero. What then?And then I have created a product; a complex web app, reasonably high barrier to entry, started building a SEO presence, have a user base of 4000 people. How do you value that?And of course if they deliver on expectations they’ll add a lot of value to my company if I sold in a year instead. see hubwealthy.com/wealthy