I think I've seen the first concept before, possibly even in one of the Secret Histories. Your execution is somewhat awkward. There doesn't seem to be much point to gaining a copy and returning the one you played. It would mean that it wouldn't give you a second play if the pile had been empty, you wouldn't be able to use it on Necropolis or any Knight, and usually it would fail on Ruins as well.
Better wording would be:
Delayed Throne Room
$4 - Action-Duration
You may choose an Action card in your hand. Play it now and at the start of your next turn.
The FAQ should clarify that the chosen Action card remains in play between turns. This should be fairly intuitive, given that Throne Room remains in play when it is used on a Duration.
Note that I put it at $4, but it could possibly work at $3 as well. This is because the combined effect is just Throne Room, but the delay tends to weaken it. This is why Caravan can cost just $4 despite it being equivalent to a delayed Laboratory.
The idea itself is quite interesting, but I don't think it plays very well. The big thing is that it can lead to a lot of confusion. Suppose I play DTR on a Wharf. What should happen is:
- I play DTR-Wharf, getting +2 Cards and +1 Buy.
- Continue turn as normal.
- Next turn, I get +2 Cards and +1 Buy from Wharf as a Duration.
- I
additionally play Wharf again, getting another +2 Cards and +1 Buy.
- Continue turn as normal.
- The turn after that, I get +2 Cards and +1 Buy from the second play of Wharf.
That may still seem simple enough, but it can become a nightmare to track if you play more DTR-X during those turns. It can already be difficult to remember what Durations were played last turn and which ones were played this turn, but DTR can confuse it even more.
But that's not the end of it. You could also play DTR-DTR. My head hurts just thinking about it.
It is still an interesting idea though, so it may be neat to test it as an "online only" card, where the computer can help track everything correctly.
As for the second card, Drab's wording is definitely much better. I may be mistaken, but I don't think I've seen this concept before (of paying to temporarily use a card). I like the idea.
One potential problem is, again, Durations. If you use this to put a Duration in play, what should happen is that it should still be returned to the Supply, but you get the bonuses next turn anyway. This issue already occurs with Procession though, so it's not a huge deal. (And it doesn't really affect your original wording, but Drab's is better despite this issue.)
Another item of concern is how it plays with cost reduction. If you can freely copy King's Court with no limit, that gets kind of wild. BoM is worded such that it can never copy King's Court. But maybe this isn't much worse than other situations that can arise from the official cards.
Strategically, I have to say that this is probably far too weak. BoM lets you copy a $4 card for free while this one costs you a Silver. BoM's strength is flexibility, but this card gouges you terribly to achieve the same. Drab's wording lets you get +$2 which can be a helpful fall back, but it's still not great. The only way this beats BoM is that it can mimic more expensive cards, but again -- it's very expensive to do so. While getting a play of those cards might be nice, consider the alternative -- you could just outright buy that card. Sure you don't get to play it
now, but then you have it. You don't have to keep paying money to use it.
The idea is neat though. Maybe there's still way to make it work.
PPE: The reason why Drab's wording is better is because it follows an official card. You are trying to create your own mechanic for playing Treasure in the action phase, but that's already been done with the promo card Black Market. Doing it a different way is messy and confusing. If you aren't familiar with Black Market, you can read up about it on the
f.ds wiki.
You seem to have a slight misunderstanding about how treasures work. When you play a Treasure, it generates coin in the same way that an action card would. Even though you play the Treasure in the action phase, the coin is still available to use in the Buy phase.