Some "extremely rare" coins in Spink aren't and some coins are priced as if they came up every day whereas in fact they are extremely rare. To further muddy the water, the rarity values assigned in Freeman, Rayner, BMC etc are frequently at odds with the number of pieces seen at sales and are really only an indication of what was considered rare in 1964, 1970, 1972, 1985, 1992 etc. Post a couple of pictures and someone will be able to give an idea of scarcity together with a grade and ballpark value.