Stairs can have a platform or can go straight, building size makes the difference on how much space they take up.  
 
Workbenches can come with or with out peg board and go on either the side or the end of any shed, garage or cabin  Peg board can also be installed separately if you don't need the work bench.  
 
Shelves can be built into your shed on either the sides or the end and can be 1, 2 or 3 tiers tall. 
 
Prices vary by size length. 
Prices are available with the rest of your finishing package on your quote as it varies by size, style and options.