I came across this post about a dollar store that is increasing its prices:

On my last visit (to my local dollar store), I saw a sign on the door, telling us customers that owing to the cost of things generally and energy specifically some prices would be raised to $1.25 and others to $2.

Part of the marketing that makes dollar stores work is the idea of a simple, low cost amount. It doesn't seem to work well when you start changing that. I understand that these stores must be under extreme price pressures with the increase in costs, but if they leave the original marketing approach, I think they will have even more trouble surviving.