I believe that was technically three clues, though the first one I had already surmised. Something that doesn't require much energy, but I will get a lot of use from... "Velvet or leather" makes me think of clothing, though not necessarily, of course...

( Can you hear him thinking, Lestat? He's so pleased to have a mystery, it's a gift all on its own. )

You really needn't buy me things so often, you know. I have far more than I need, you've seen to that.

( Just so Lestat remembers that he is Lofty and Poetic and Above Material Things. He'll still use them, though, obviously. )