UKC

This seems to be the best deal I've found so far:
Ebay item 380260654388 (can't put link due to auto-anti-advertising rules.)

£67 for 1000 delivered.

Inside, so don't need stainless ones really (though it's not the driest of buildings, hopefully should be ok).

In reply to geebus: Try you local hardware place, or screwfix/toolstn etc. We have a place in Penrith called ACE fixings who are fab.

In reply to geebus:Hi I've sent you a message.

Unfortunately toolfix, tool station etc are pretty pricey - but it seems grhgrant can help me out nicely!

In reply to geebus: Holdz, entreprise, king kong, Zig zag walls... any of the climbing wall manufacturers

In reply to geebus: try a fastenings company. Something like tr fastenings.

In reply to geebus: a decent engineering supplier like bearingman (now Hayley)or orbital fasteners can do good prices especially for 1000. zinc plated (BZP) is cheaper than stainless steel and worthwhile even inside in my view.

In reply to geebus: Hardwear firm locally by far the cheapest (£35 i think).

In reply to geebus: Eurofasteners,weymouth supply most climbing wall manufacturers

In reply to geebus:

Are you sure you're getting M10 tee-nuts? I've never found M10 in screwfix or Tool station, they only ever have M8 and smaller.

Entreprises are fairly cheap...

Sorry, didn't even look properly - just did a quick search and saw the M8 or whatever were a lot more expensive, so presumed any M10s they sold wouldn't be massively cheaper than smaller ones they sold.

So far I've got the following prices for 1000:
orbitalfasteners: £120.70 inc vat (mild steel, plating not mentioned on website.)
Eurofastner: £64.28+vat+£12 postage
BMI-Hayley (Bearing Man): £49.60 + VAT = £59.52 - including postage for BZP

Zigzag couldn't get a competitive price, but where very helpful overall.
Hangfast (just down the road from me) also couldn't match the above prices.

Thought I'd update here to help anyone else in the same situation.