Yes. There are some things that people can't realistically do without. I worked as a stringer for the local paper for some years. In this capacity, I covered local water / sewer authorities. The typical cycle went like this. The authority raised rates to meet their costs. People used less to try to cut theirs. The authority took in less money; so they raised the rates again.
Also, in the US, these contracts go to the lowest bidder. The bidding process is not exactly always the most honest and truly competitive.
The combination of these two things is why I fully expect ink prices to go up.
Ink and printers are complementary goods. A person can't buy whatever ink they want, they need the ink that goes with their printer. At the same time, if ink prices go up $5 per cartridge, few people will go out and buy an entirely new printer.
Inelasticity of demand from complementary goods comes into play when the complementary good is relatively very expensive or difficult to replace.
Consumer printers cost about the same as an ink cartridge or two. Consumers aren't "stuck" paying for more expensive ink if manufacturers decide to start screwing them on the price.
[edit: wanted to add this]
Even with the ridiculously complementary goods of automobiles and gasoline, more expensive gas shifts consumer demand away from gas guzzlers.