Just a couple of quick tips:
1) Target's system allows them to scan 4 coupons per transaction. At least at my local store. The first time through the line, my family of 6 tried to buy 24 cards. The cashier was only comfortable letting me use 6 coupons (and I don't push them to do anything they aren't comfortable with). But the systems would allow her to scan only 4 coupons, so she had to do a second transaction. Anyway, I only mention this because you may not have to do a separate transaction for each. BTW, ultimately we went back into a different line and the cashier was fine scanning the remaining 18 coupons in 5 separate transactions.
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I was only allowed to use one coupon per transaction. The coupon says that quite clearly and the cashier cited it. Just an FYI. So I made a $130 purchase (one item) and used one coupon on it.