The only things
GW do for a reasonable price are the paint brushes (you have to do your own quality control on them though
lol). For the few quid, £3-5 depending on which size, I havent found a good quality sable brush for less. (Also their drybrushes are quite good, I dont think ox hair is very popular with artists brushes
tbh)
There is however much better quality ones out there

quite a few notable brush manufacturers (windsor and newton springs to mind) but you will almost surely be paying double what
GW charge for similar one. Just my general experience with
GW brushes is that they retain their tip longer than equally priced 'cheap' artists sable brushes provided you pick out the brushes that do not fail quality control while at the shop (it really seems like they do not bother to do QC at the factory sometimes haha)
Everything else they sell is available much cheaper elsewhere, at hobby stores or arts & craft stores, model railway stores, outside on the floor (sand, pebbles, sticks etc random basing materials).
The craft knives are a joke... Xacto blades are cheaper, and Xacto is a right rip off!!

Try any tool shop/hobby store for your tools.
Files and clippers will most likely be in the same store that stock the blades

maybe a pin-vice too, drill bits for pin vices are just regular drill bits in a small size, you cna probably get a set of many sizes from a shop that stocks the vice rather than just 1mm like
GW give you. (I like 1.5mm for boltgun barrels for example)
Even their figures are available 25% cheaper online, aslong as you dont make the mistake of buying it from
GW directly!
We've got Darksphere.co.
uk in the
UK, and Im sure theres a few in the states. (Its probably not cheaper to pay international shipping too!

) - Everyone should take advantage of these stores while
GW are still letting them stock their products, I'm sure we've all seen the trend of
GW discouraging 3rd party stockists all over the place.