Quote for hard landscaping in London garden

SimPaul

I have a garden in West Kensington, London approx 60' x 25' that needs some hard landscaping. I've received 3 quotes - one at £3k (accompanied with what seemed to be a child's drawing of my garden); one at £11k (£11k!!!!) and this one:

Lay decking area 5m x 3m on pressure treated substructure £970
Extend existing patio area 6m x 4m with Indian Sandstone £1,130
Labour for patio and decking £1,690
Create path stepping stones between 2 areas lab+mat) £330

Total cost £4,120

Includes no planting, other garden clearing etc. The other 2 quotes were ridiculous (1 for lack of professionalism, 1 for price) - but I can't help but feel it's a lot of money for putting down some decking and a patio extension.

Any opinions?

kph100

Seems reasonable to me.

were getting 36 sq metres marshalls sandstone, soldier course, linear drainage, for £4120. plus dropping 1 drain.
includes marshalls guarantee.