the uk mil issue rifle? hell i don't know that i've seen them for sale more than a time or two at the most. don't really know value. give bauer arms a buzz, they'll prolly know.
You may want to PM Stacey Blankenship (Blanksguns here on the Hide). What year was your stick? and how many rounds down the tube? Does it have iron sites? Is it dovetail mount vs. Picatiny rail? Collapsible stock vs. adjustable vs. fix stock? All of those factors are part of the equation to determine the value of your stick.
A brand new AIAW with all the options can go as high as $6000+ and more.