4. (12 points) I) Posted by: Grant Gould on a Web Blog Purchasing some software on Buy.com about a year ago, I found that the listed prices for the same software were different on the front page of the website ($49), on the search-all- products results page ($39), and on the searchallcomputer games page ($29). These were, in order, progressively narrower searches. II) From the Wall Street Journal: HP has quietly begun implementing "region coding" for its highly lucrative print cartridges for some of its newest printers sold in Europe. Try putting a printer cartridge bought in the US. into a new HP printer congured to use cartridges purchased in Europe and it won't work. Software in the printer determines the origin of the ink cartridge and whether it will accept it. Please use the two examples above to comment on the following: (Please be veg specic in applying the two examples above for the discussion of the comments below) i. Price discrimination increases a seller's prots. ii. Why, then, don't all sellers engage in it