There is going to be lots of problems with this. Knock offs tag switching just to start with. I cannot imagine TMs being trained to ID and evaluate clothes.
I bet the clothes will be shipped off and the guest will later get the gift card or email on what funds will be.
Meh you can't just bring in any used clothes they want like snobby high end in season stuff so if you can afford Gucci with your Target salary by all means please give it to them!