This question was posed to me by a friend shopping for a coffee grinder. The $44 and $175 refer to two grinders we sell, a $44 La Pavoni burr grinder and a $175 semi-commercial Bunn grinder, the $19 grinder is a coffee chopper he saw at some store. The major difference is that there are blade coffee grinders (coffee choppers) and burr coffee grinders. Blade grinders are those little cylindrical appliances with a whirly blade at the top, like a mini food processor. Burr coffee grinders grind coffee using sets of sharp interlocking teeth rotating in opposite directions. Using a burr grinder, the coarseness or fineness of the coffee grind can be controlled by varying the distance between the teeth. The closer the teeth, the finer the grind. Using a blade grinder one is to pulse the whirling blade less for a coarser grind and more for a finer grind. As you can probably guess, the burr grinder produces a more consistent, uniform, and accurate grind. So is this more uniform grind worth 25 bucks? Oh! It, and the added convenience, ease, reliably, and durability of a burr grinder make it worth way more then that additional 25 bucks! Having coffee ground inconsistently gives a big spread of particle sizes, some pieces to small, some to large, some just right. The small pieces of coffee get over extracted and the large pieces get under extracted. While the just right sized pieces get extracted well, the under and over extracted parts balance each other out as much as a steak frozen on the inside and charred on the outside. They don't. But the more you can get the grounds to reach a uniform size the more even your extraction will be and thus the more delicious your coffee. Kudos to those who grind their own coffee whether it be with a burr grinder, blade grinder, or a paper bag and hammer. If you have the budget, I would suggest retiring your blade grinder to making fresh chopped spices and pecan and almond butter and upgrade your coffee grinder to a burr model.