Just got an Email back from http://www.pocketfoldinvites.co.uk/ as I emailed explaining what I was hoping to do and this is the info they sent back -

Hi, It depends how you want your invitations to look in the end, if for
example you want the inserts to look like those pictured on our Indulgence
design in our design gallery for each invitation you would need: One pocketfold
(obviously!) 89p eachOne 125mm x 125mm silver insert ( boarder) 20p eachTwo
120mm x 120mm white inserts ( one with invite details, one with map) 20p eachOne
120mm x 100mm white insert (taxi info)15p eachOne 120mm x 80mm white insert
(R.S.V.P)10p eachOne monogram card approximately 50mm x 50mm 8p eachWe cut all
of the card ourselves so you can pick and choose the sizes to suit you. Please
do not hesitate to contact us again if you have any further questions. Kind
regards Kelly Edgecombe http://www.pocketfoldinvites.co.uk/

This comes to £1.82 per invite, I don't think thats to bad is it? Got to now find out how many I will need to make.