Cheap components Register

I'm starting a new thread to list where to get bargain bits that aren't generally available at your local model shop. Please add to this for those hard to find bits and bobs...
E.g.
For the "pneumatic retract brigade" 3mm Tee's can be really hard to find, and a £2 per pop (assuming a bag of 10) this is 1/2 the price I have found elsewhere.

Or these lovely little 3mm permanent Tee peices...