Star Munchkin: complicated situation

[Ymar]

I found some powerful combo in this game, but I'm not sure if it's actually working the way i think.
It requires 4 cards: Paradox In A Box, Plot Device, Pink Stamps and Trader.

When it's another players turn and he found a monster when he opened a door, I play Paradox In A Box and it's my turn now and I fight this monster. Paradox In A Box goes on the bottom of the discards. After the fight I use the Plot Device to get Paradox in A Box back, I discard Plot Device. I use Pink Stamps to get Plot Device back and then I use Trading ability and discard any item to get Pink Stamps back to my hand.

Aaand this way I am playing till I have items to get rid off (which I can get by winning fights) or till somebody stops me with Time Wrap.

Is it correct?