We also got the counter offer for our sailing in Norther Europe. From Aurea to YC Deluxe, the upgrade was 1400 EUR. (Originally we payed 2000 EUR). But we will also be 2 adults, with 2 kids (16,12).
I would do it, if I were you and can afford it.
Last year we were upgraded WITHOUT paying from Aurea Whirlpool suite to the YC Duplex suites... That was amazing!