The Tan G is more rare than the turquoise G. It was made approx. 1967-1968 and then the 1205 came out after Consolidated Foods acquired Electrolux and wanted a complete, "make over". As far as I know, both vacs are identical with the difference being the visable colors.
Tan G's have sold on ebay and privately for a low of around $25 to over $300. A lot depends on condition, if all tools are complete, if it has the original box and owner's manual, etc.
They are a nice addition for any collector and as time marches on, I suspect we will see less and less of them. There was even a Tan G Hospital model. Charles Richard Lester has one and has pics on his web site of it. If you have not visited his web site and seen his pics and text, you should definately take a look.
Charlie W.