I choose to use Instant Ink because I don't print a lot and it still beats buying the carts. HP ships them to me for free and automatically before I run out and gives me return postage for the empties to be recycled.
They also don't have different rates for B/W and Color so I just print everything in color.
I dont stress over $1/mo (or $1.50/mo if this increase hits me). I've had this printer for 2yrs on the cheapest plan and I've still not paid the full price of a set of cartridges.
I'm sure I'll be down votes for saying anything positive about the program but whatever. It works fine for me.