Sometimes convenience is the chief motivation, not cost.
the French Press I bought was on sale for $12...its convenient(steeps for 5 minutes). I let my tea steep longer.
It may be convenient for you, but it’s not for me. I’ve got two of them and never use them. One I used for about a week, the other I’ve never taken out of the box. For me, Keurig is the way to go. Everyone is different.