I live in Spain and when you go to supermarkets, all price tags on the shelves and on supermarket-packaged products (pre-cut meat, for example) indicate the cost of the product per unit (big numbers), and per kilo (small numbers), so, if you want, you can quickly and easily compare a package of, say, 136g of meat with other packages, without weight interfering. You can see easily the price per kilo of each kind of meat.