Take a look at the ryobi range. You can get a drill with 2 li-ion batteries for £90 at b&q, for the concrete stuff you need to drill, take a look at the cordless sds drill they do, it doesn’t come with a battery but it’s around £90 for the drill, and a 4ah battery is £75.
If you wanted an impact driver as well they have do 1 for £60, it’s a little over budget, but you’d have enough drills for any job and more than enough batteries.