Want to begin to play the harp?

I already have had some piano experience, and I play the flute.I have always wanted to play the harp. I'm thinking of purchasing a Ravenna 26 from Dusty Strings, but the only problem is the sharpening levers. Are they really necessary to play the lever harp? They are quite expensive when added on with the harp price, and I don't want to overshoot it. So are they a more of a necessity or convenience? Also, any helpful tips on how to play the harp would be greatly appreciated.