Honest opinion mate, but this is a Focus, it isn't a Focus RS. And because of that, even if you do keep it, you'll still know it'll never be worth a lot in time because it doesn't have that badge on the boot. So you need to consider your options.

IMO, you may as well just keep it and carry on playing with it and enjoy it. I've decided to do just the same with my mad Focus, not spending much more, but just a little in the right places as its perfect to me. Its what I want. I imagine that's your opinion about your car also.

Hope your luck changes, but I doubt it if you keep it at that price