I thought for some reason you said you had 6900xt and were all liquid cooled with hard lines.or did you change your setup without an update.
Actually, the cards are close in performance, most used 3070 I've seen listed were in about the $500 cnd or up range around here. he's what I'd of paid in USD $293.92
Your card is 500 cnd (before taxes) at newegg over here my card cheapest ads an Ebay are in the 500 cdn range. I almost never see higher end AMD card on kijiji, when they are on they always seemed overpriced.