Yes! If you already have an infinity offer you may complete a Trade directly from the Existing Offers page. If you don't have an offer yet be sure to submit your Rebag purchased item from your purchase history to get an infinity quote and then start a trade from your existing offers page.
If you already have an infinity offer, It's important you do not try to get a new quote if your bag was purchased from Rebag. A new offer will not show the infinity price if it's not specified on your submission.