An unmarked AF0210 strap and a Mark VI compass sold for £240 plus buyers premium at auction recently (January 2019), so, with delivery, totalling some £320.
This price is the same as a recently sold NOS stamped strap.
The compass and strap were in a lot together with a WWII Luftwaffe cockpit clock, stamped Borduhr 840085.
The Jedburgh or SOE wrist compass has been seen on a variety of straps, the most valuable being the stamped A.F.0210. strap, and is discussed in another post.