You can't pay for @gmail.com addresses, or else I absolutely would. If I'm going to make everyone change the e-mail they send me things at, I'm sure as hell going to change it to a non-GMail address now.
It is also not something which most people have heard they should do. It also requires you to be something of a power user to even understand. Many people are so far into this mistake that it would take time and even more technical expertise to dig out.