Sorry it's a bit late, but, A4 180g/m photo paper is what I mainly use and only pay about £1.99 for a pack of 25.
"Sumvision Premium Glossy Photo Paper"
25 SHEETS A4 STANDARD PHOTO PAPER £1.99
http://www.oemicros.co.uk/news.htmEddie and Alice
I know they also stock a thicker quality, but not sure which one.
Checkout the price list, you could ask him if he will post some.
For most things it is fine unless you do not intend to mount in a frame etc.
I have used that paper for a log time and the quality is good for most things, but for unmounted pictures probably a 240g/m paper would be more suitable.
The last purchase was from "ALDI" and was about £2.50 /25 pack.