I bought a $1400 mattress in my quest for sleep, over the Internet hence much cheaper than the mattress I tried in the store, but non-returnable. When the new mattress didn’t seem to work too well once I actually tried sleeping nights on it, this was making me reluctant to spend even more money trying another mattress. I reminded myself that the $1400 was a sunk cost rather than a future consequence, and didn’t change the importance and scope of future better sleep at stake (occurring once per day and a large effect size each day).

from http://rationality.org/checklist/

Is it rational for someone to choose to NOT buy another mattress, not because of the sunk cost, but in order to "punish" oneself (stick and carrot style) to change their behavior and not buy non-returnable, expensive things, ever again? (or to be more careful when buying expensive things)