HP, Kodak and Lexmark printers supposedly have the cheapest printer ink. The following website is very interesting and has detailed information about cheap printer ink: http://www.printerswithcheapestink.com/printer-reviews/
Kodak
If you really want to know what is the cheapest ink cartridge for a brother printer because you need to buy a cheap replacement, then you should try HP ink.
There is no different chemical from brand to brand on printer ink, so no need to worry. The ingredients being the same, you should have no problem finding an ink refill that will work with your printer, no matter the brand.
Yes, you can certainly substitute store brand ink for HP printer ink. Most of the time, store brand ink will be indistinguishable from HP ink. However, refills can be less desirable.
If you have ran out of printer ink and are looking for the cheapest ink brands, a suggestion would be to look in a local computer repair shop and ask around.
Brother makes printers that have decent priced ink cartidges, but it uses so little ink you rarely ever have to replace them. Mine has lasted over a year.
I do not recommend using another brand of ink cartridges for a separate brand of printer. The printer may have a different process of dispersing the ink in a different way then how the cartridge for another printer might.
"Printer ink HP" is printer ink cartridges made by the HP (Hewlett Packard) company. Recently a ruling by the International Trades Commission found that several companies including, Microjet Technology Company Mextec America and several others, had infringed on patent rights owned by HP to build the expensive ink cartidges.
You can buy the cheapest ink for a HP printer at Staples or OfficeMax for about thirty dollars each depending on what kind of ink you need and if you have a reward card with any of those two stores you can get a couple cents off.
Nearly all printers will take a cheap printer cartridge. Many machines however will only guarantee their product only if the ink cartidges specify by the manufacturer are used.
The Epson 825/925 has the lowest cost replacement ink cartridge.
You can find the cheapest laser cartridge for your printer at amazon.com. They offer a wide variety of affordable ink and laser cartridges for every printer there is.