Hi niamh...thought I'd wade in here, as only this morning I was at the Bobbi Brown counter putting in some new bits to my BB palette. I've never grown up in this regard...neat kits with everything you want in 'em is just dandy!
As you probably know, you buy the empty palette, and insert individual 'trays' of eyeshadow or blush powder. This way you get it exactly as you want...I dislike having lovely palettes with the odd colour I never use....damned stupid, but I guess I'm a bit obsessive! Anyroad: with the BB one, I have more 'trays' than the palette holds, cos I do favour one shade over another for a bit then revert...so you can swap about as your whimsy takes you.
Only trouble with this idea is getting Santa to get the correct shades. I can't think how you might get around that one.
Happy shopping anyway