Soldier's Companion for under £5- until 08 March

[Agent Brown]

http://rpg.drivethrustuff.com/product_info.php?products_id=59093
Colonial/VSF rules. PDF download, part of a sale at DriveThruRPG.

[Sterling Moose]

I managed to get a hard copy at a bring and buy sale last year for $8, it's a fantastic resource even if you don't use the rules.

[Count Winsky]

I just purchased ($7.46 USD) a copy (downloadable version) from Drive Thru RPG.  The front and back cover are in color, but all ofther pages are in black and white, but it gives a good explaination of uniforms.  I wish it would have been in color.  Here is link to order below. 

http://rpg.drivethrustuff.com/product_info.php?products_id=59093

[Gluteus Maximus]

A good set of rules and as Mr Moose says, also a very good reference for Mars-based VSF fun.

Well worth having at that price, as you can just print out the stuff you need for playing games if you don't fancy doing the whole book.