Have a look through these -- they're the main stockers I use in the UK and are all fantastic. Have a look at what he has in his shave den, see what scents come up that he likes. Maybe an aftershave splash would be nice, pick something you like and its a win-win. Fine aftershaves are all a hit and are on one of the websites I linked you, just make sure he doesn't already have the specific scent you get him if you do, as they've just gotten to the UK and might have caught his attention, they are all fantastic -- just read the descriptions and try and maybe slip some into conversation and see what he seems to like the scent profile of. They are all based on commercial scents from big-name brands like YSL and Creed Aventus, so you could find out what the one's you look at are inspired by, and go to a shop that stocks them and smell those.
With that kind of budget I think you should get him an aftershave splash and maybe a soap or cream or two to go with it. For those, especially since you are in the UK, I promise you cannot go wrong with Martin De Candre soap, they are french shaving soap makers that are probably the most respected in the world, The traditional lavender scent or the Fougere are sublime, I've never found better -- you would have to order from their french website (so be wary of translation issues) but you can't go wrong with them, they last for ages and are just the peak of luxury. The important charges are quite steep because of the glass containers but you'll see the look in his eye if you get some for him and thank me. You could also look at what are called artisan soaps on the second two websites I linked you, they are quite popular with shaving enthusiasts and are affordable and perform well. For a cream XPEC is a favourite, they're stocking it on Connaught shaving so that makes your life very easy! They are almost never stocked in the UK and no man should have to live without trying some.
With those things you give him something luxurious that he can look forward to wearing on special occasions and some things he can use everyday that will yield great results every time. I really think it would be quite difficult to get him a brush or razor that would appeal to his specific needs, especially if he has some favourites he uses every day. I do hope this helped, good luck with whatever you choose but you definitely came to the right place, my SO would never find this place on her own, it's a minefield of information. Don't be afraid to post again to shortlist some suggestions, people here are all friendly guys.