It's coming up to a year since we got bees and it would be very hard for someone to buy me something without knowing a fair bit about how we keep the bees. I'd guess most people would have a general bee keeping book or two if they needed them although new books are often coming out so look for latest releases. It's hard to buy hive parts unless you know what hives they use (we're constantly buying hives and parts but then we have room to expand). Perhaps a book on making hives from scratch?
I'm trying to think, if they use rubber gloves and you know their hand size another pair would be useful. Wax moulds again could be useful if they have plenty of wax and like candles or even a solar wax melter if they don't have one and you have plenty of money.
I expect many bee stores sell gift vouchers if you get stuck.