filament:

http://www.3ddynamics.co.uk/ – gives a good price on ABS and PLA. There are also several colour choices.

http://www.lulzbot.com/?q=catalog/plastic-filament&gclid=CIjjzqjhnbkCFTPItAod434A3Q – has a wide range of ABS and PLA filaments, with ranging prices and colours, even offering a wood based filament. It also sells two lulzbot printers.

http://store.makerbot.com/makerbotr-water-soluble-pva-1kg-spool-1-75mm.html – on the Makerbot store it is possible to buy 1kg of PVA filament for $90 which is expensive compared with PLA and ABS, from their website and others.

http://formlabs.com/collections/all – this is the resin for the Formlabs 1, but it is very expensive at $149 for a litre.