What Smiffy linked to, though
here's a more UK site
I got that set for a tenner when I bought a multitool there last weekend.
I got a set of torx drivers years ago from a market stall in Leeds for fiddling with the lock on the lenses on my sunglasses, among other things and they've lasted well. Cost me all of a £5, I'll be willing to bet eBay has something similar.
Edit - found the same thing on
Toolstation's site for a wee bit cheaper. The caveat of these things is you'll need a screwdriver head/drill to slot them into.
EDITED: 26 Feb 2020 19:55 by GRAPHITONE