You have sheets which are worth more than face value such as the 5¢ Space Twins sheet. Keep in mind that minimum value in the Scott Catalogue represents work by the dealer to sell you the stamp and not its actual value which can be close to zero or 1¢. Again new issues are typically listed at double the face value for the same reason. If everything you
inherited is in sheet form you might do well to figure out the total face value before you go to sell them. Many dealers will do a guesstimate to save time, typically on the low side. You can defend yourself by doing your homework.