Artificer needs to be higher.
I had it at 6. I'll probably regret that but I don't yet.
I don't think Top 10 is at all unreasonable for Artificer. It's criminally underrated on this list. It's one of the most reliable and fastest ways to pick up key engine pieces right when you need them, and with decent draw it can even be a great late game VP gainer. Worst case it's a $5 Peddler which isn't too bad itself. Very, very good card.
A 5$ peddler is not great- see Treasury. The on gain-effect is probably decent but I don't think it's close to the strength of the top 10cards (except maybe in Pool games)
$5 Peddler isn't great, what I meant by that is when you don't need the gain effect, it is still a net positive to have one in your hand vs no card. The only opportunity cost is not getting another $5.
Artificer is really a card that is better than it looks, you really just have to buy it a few times and it will click how good it is. Can't tell you the number of times my hand is like Artificer / Village / 3 cards I don't give a shit about, I draw a 4th junk card, topdeck a Smithy, play the Village, and now my previously dead turn has hit the ground running. Or one game, I recently drew my deck, used Artificer to gain an Expand, which I immediately drew to gain / buy the last two Colonies and win. You buy it not clear on exactly when you're gonna use it and suddenly your engine is twice as reliable and you have no idea where all these components came from.