British East Africa Specimen 4.5 Anna

Any info about value pls

Well, it is Scott #79. A set of 16 stamps (#s 72-87) overprinted with "Specimen" catalogs $325.00, compared to regular set catalog $537.75. Nice looking stamp.
My catalog is 2013 Classic.

Sc #79 cat. $15 in 2014 Specialized.

Esmak: welcome to the Forum!! Lots of good information to be had here.

As luck would have it, the only Stanley Gibbons catalog I own is the East Africa; 2nd edition; published in 2010. This is British East Africa Gibbons #71, cataloging L 13 mint and L 16 used. The entire Specimen set; 65 S to 79 S; catalogs L 275 mint, with no price used.

There is a new edition of this catalog, which I don't have. I bought this one to help me with all the plate varieties on the Kenya/Uganda/Tanganyika KG V and KG VI issues.

Typically they create the same number of specimen stamps for each value, unlike the postal version where the create the number based on expected sales. Because of that high face value specimens are often cheaper that the nonspecimen examples, and the low face values are just the opposite. A good rule of thumb for pricing is to take the set price and divide by the number of stamps in the set, then bump I down a little because it's a hassle to build a set from singles. In this case there are 15 stamps in the set (Scott shows 16, but one is essentially a shade difference) so if cataloged at $325 for the set individuals would likely be in the $20 range each.