An Embarrassment of Riches
Here, you can buy any combination of blocks: assemble your own set, replace a broken block, or choose from the many special shapes. The cost of a "set" of blocks is the sum of the prices of the individual blocks in the set. These are the same prices that are used to compute the prices of the sets; except for the set discounts, they are they are no more expensive. Some shapes simply cost more than others because they are bigger or more complicated.