When you buy a new printer (Inkjet or Laser, in particular) the cartridges in it are typically half full. The shock comes when the replacement cartridges cost nearly 60% of the new printer cost!
If you took these "original" cartridges down to Cartridge World they can fill them but these cartridges are not Full Size. Hence now manufacturers are calling their standard cartridges "High Yield".
For example a HP Laser cartridge in a printer has a life of 2,500 pages. Replace the cartridge you were supplied with in the new printer with the manufacturers standard cartridge (High Yield) and you get another 1,000 pages for about a fiver.
In manufacturing terms the cost of the container is a few pence difference in terms of extra plastic and the contents, ink or powder, is similar. You may find for example that a Canon Compatible inkjet cartridge is the same price for 30ml as 60ml which tells you something.
Remember to donate the old cartridge to a charity and then refill the new one from now on.