Why using a trading blade program is not the best or most economical use of your money.
If you are in desperate need of a sharpened blade and can't wait for it to be resharpened, then trading in your dull blade makes sense. Although, in most cases, you will be paying a very high premium as you will see below. Your choices are limited as to what the trading company and the retailer have in stock. It's very possible that you may not get an equal or identical blade to what you are trading in.