Recently found a different supplier form Le Prevo for leather hides - I've just completed an order with them and am very happy at price and service (no, I don't have anything to do with them )
Minimum order is 1 kipside, but there prices are very reasonable - I got a 10.25 sq ft hide of 2.5mm leather (veg tan) for 25 quid including postage - I went for what they call 'grade B' which they say has small flaws which mean its not suitable to be used as one large piece in working, but to be honest, I can't see any flaws in it
When I ordered they didn't have any 3mm hides, but they did say they'd have some in soon.
Their prices seem to change often, so email them for a current list...
Just thought I'd share