Seems like a normal range for these types of airplanes...
A320 is 275/o.76
And like ImbracableCrunk said good to do what the book says but a good idea to find out what she says (:
Two reasons why these speeds are selected
1. It's the idea design speed and giving adequate buffer from high speed /low speed buffet...
2. There's an adequate margin from Vd as its a guru mantra to never go below the recommended speed and small increase is always preferable.