Note: I'm not talking about current, paying customers. How you handle pricing changes for existing customers is a different topic. (personally I keep existing customers at the price they signed up at)
Here I'm talking about prospects. People who saw your old pricing, didn't sign up, then revisit the site months later and find that pricing has gone up.
I've had a few emails like this and I'm always a bit unsure how to handle them. Do you offer them the old price? Or is it new price only; take it or leave it?
I think there's good arguments for / against both approaches - I'm curious what you all think.