Why cheap? How many do you need?
You can always negociate with any replicator...
I've found that working with brokers or other 'real' cheap ways always results in headaches.
For our normal work we need 2000 pieces, our biggest job was 15.000
Now a cheap replicator is 10 cent a piece cheaper than the good one.
For a difference of 200 euro (or 1500 euro in our largest job) i do not want any hassle.
I'm most of the time working with DocData, they're also in the UK
http://www.docdata.co.uk
hth