Apprentice by itself is a
very good $5 card. One of the best ways of getting rid of your starting Estates, and once you have a few in your deck, your Coppers should disappear fairly quickly as well. They are an excellent way of getting rid of cards that have become obsolete (cursers, trashers etc), and if all else fails, you can often Apprentice an Apprentice for +5 cards.
The obvious drawback to Apprentice is that it needs fodder, expendable cards to keep it going, and the more useful these cards are to feed to the Apprentice, the less expendable they tend to be.
And then there's Hoard. Hoard presents an almost opposite dilemma: is it worth buying some early Duchies and Estates to get some Gold into your deck? Sometimes it is, sometimes it isn't.
When used together, Apprentice and Hoard solve each other's problems very nicely: Hoard puts green cards in your deck that you don't really want, Apprentice takes them out with a very nice benefit. And in the meantime, you become very rich.
I recently played a
Colony game with both of these cards present. Soon enough my deck consisted primarily of a few Apprentices, a bunch of Hamlets, a bit of cash and a Hoard. On turn 10 I drew $5 with a Hoard, and I had a decision. I wanted a Gold, but I wasn't particularly keen on the Duchy so early in a Colony game. But, having a bright idea, I bought the Duchy, gaining a Gold. Two turns later, I Apprenticed the Duchy, which allowed me to buy a Province, gaining another Gold. Two more turns later, I Apprenticed the Province and bought another Province and two Estates, gaining three more Golds. Pretty soon I had Colonies, two of which I trashed to my Apprentices, allowing me to buy a bunch more with all the Gold I had amassed, and of course, gaining more Gold in the process. I ended the game on my 19th turn with 6 of the 8 Colonies, having trashed the other two, and won 70-23. I had 16 Golds, all of which came from my single Hoard.
Of course, my game was helped greatly by my Hamlets, and the more green cards I had, the easier it was to discard for the +buy. Would it have worked without a +buy? Probably. In that case I imagine you'd want to feed some of your excess Gold to the Apprentices, and probably at least another Hoard would have helped to overcome this loss of Gold. But of course, it's much nicer to trash a Colony for 3 Colonies and 3 Golds than it is to do so for 1 Colony and 1 or 2 Golds.
Now obviously trashing a Province or Colony, particularly towards the end of the game, can only be justified if it allows you to at least make up the points lost, and preferably gain more. If most of your non-replacing cards are Golds, then +8 or 11 cards pretty well guarantees drawing enough cash to buy at least one, and probably two or more of the trashed card.
