It's late, but alternative options for silent keyboards (somewhat quieter than that of the Logitech MK295 that was chosen by Vanilla) are:
Logitech (K740) Illuminated Keyboard (wired). This one is probably the most quiet of them all (as the keys are also surrounded by some felt around each key, which helps baffle sounds coming from it and reduces the chance of you hitting the keys too hard to create noise from the impact, but the issue is that it's wired (USB), has backlit lighting behind each key but it's white only, and it has some poor N-Key Rollover (including lack of Shift + W + Space, which was specifically disabled). And of course, in the UK, you're looking at £70 odd to grab one new.
Logitech MX Keys (S). This one is almost as quiet as the above one, as they both use Scissor Switches for the keys, but the construction of the base in this keyboard makes it "echo" a bit or enhances the sound made by key presses (this is because unlike the K740 tere's nothing under each keycap to help absorb the impact from the press). This results in the keyboard sounding "louder" (or more noticeably at least) than the K740 (when you hit the keys hard enough where the base transmits the sound out, so a suitable surface and desk is recommended to keep the noise to a minimum), even though they use the same switch type. This one is also wireless, backlit (and fixed some issues from the original MX Keys) and has decent N-Key Rollover allowing it to be used for gaming as well. And if you look around can be got for around £85. Do not get the original MX Keys version as that one is plagued by a host of issues where there's no obvious fix for the end user other than exchanging it out for another (goes for around £80 if you look around - so might as well cough the extra £5 up and get the better one).
But of course, these are also pricier than what OP asked for, so unsuitable for them. But if anyone is after a really silent keyboard, these are options available from the Logitech range.
is there a poor mans version?
