Purely from an energy usage standpoint, the breakeven point between going with a variable-speed vs. a 2-speed is around $0.20 per kWh. Aside from energy usage, other factors to consider in deciding between a 2-speed and VS pump include the number of water features and how much control you want over each of them. The more water features you have and the more you want to control them individually, a VS pump will give you more options. OTOH, if you don't have many (or any) water features, the 2-speed is the better choice, especially given your electric rate.