Okay. Comments.
Count is significantly too high. I've gone over this.
Catacombs should be above Rabble, slightly. Let's break it down. Both are smithies. Rabble gets the attack, which, if they are going big money, is going to be pretty painful if you can repeat it. Catacombs gives you the filtering. First of all, this directly counters the top-of-deck-mucking of Rabble. But it's also always useful until you are drawing the last three or fewer cards of your deck, whereas Rabble's attack is useful to skip past good cards, if it does that. Each play of Rabble typically doesn't worsen their top-of deck quality by all that much (on average).
So Rabble chains, with LOTS of Rabbles, are particularly potent against, say, slogs, but it's pretty rare you get such a matchup, and in general, Catacombs have a bit more utility. Just off of this, it would be very very close, though I think I would give the tiny edge to Catacombs. The trash ability makes it clear for me, though still not a very large difference.
Lab is, I think, a bit too high, and stables a bit too low. I definitely like stables more overall. In either case, you don't want to build an engine just on the backs of one of these too often, and when it's more of a supplement or general good card, stables is just a bit better. The ability to trade what is usually a copper for a random card of your deck generally outweighs the chance of the no-treasure disaster. The NTD does suck, of course, but you build your deck around it.
Vault seems too high. It is excellent in Big Money, of course, but not so good for much else (eh, it grabs GMs); it is totally hosed by discard attacks and/or colony games, and the drawback is pretty significant in quite a lot of games. Embassy should definitely be better. It's a touch worse in a head-to-head BM matchup, but this is slight, and quite frankly, this situation is rare, and Embassy is better for almost every other situation.
I would put apprentice below Lab, for sure. Probably not much below, but below.
Upgrade should not be this far above Junk Dealer. I think that's mostly based on Junk Dealer being too low. I actually think I would put JD a slot or so above upgrade, but it is really tough. I find it strange to say that upgrade should be 'way way' higher, though, considering it's at 19 and a lot of the cards that are left MUST be better than it, as well as, I think, some of them we've already seen.
Bandit Camp isn't so much better than than Bazaar. Indeed, in most engines, I think I usually even prefer Bazaar, as it's easier to draw with. Of course, BC is pretty good even in other situations, whereas Bazaar is fairly marginal there. So BC is probably a touch better overall, but they're close.
Rebuild - I do not understand this card, other than it is strong. Definitely underrated here, but I am not sure how to play it. Can someone write an article here??
I agree with Bazaar>Festival - the buy is not so important as the extra card, usually.
Haggler vs. HoP. Well, I think it's probably pretty obvious that HoP has more upside, but Haggler is better more often. Actually one might compare Haggler to BoM, in some ways, being dependent on how good the cheap cards are. Uh, I think I would nudge HoP a touch higher than Haggler, but it's close - I certainly don't blame people for going the other way.
Counterfeit - I think this guy's being underrated. But, I might just write a little article on him.