Oh my goodness, you've been posting for over a day xD
1) Unfair to them both rarity and demand wise. Obviously, it doesn't add up rarity wise. Demand wise, the two Mains in there have average or low demand. The UR Pineapple is only two tiers below the Nons, and technically worth two Sorbs and a Green Toxic, though it'll usually go for a Blue Toxic or CEG tier, due to low demand. I wouldn't accept if I were them, even though you have a few lower value high demand pets on your side.
2) Obviously unfair to them rarity wise, and even demand wise. The Cheshire has very high demand, but it's gone down a bit, and they usually go for lower mid Advents. Personally, I always trade mine off for T7+, but then again, mine usually take a while to trade off cx If this is the right partner you're dealing with, they would probably accept, but most people wouldn't since that's a bit extreme.
3) They overpaid by a lot. The wig is worth 5C$, their '10 rare, even though it is a "low demand" horse, is worth at least 15, if not now 20C$.
4) Overpay rarity wise on your part, fair or underpay demand wise. The UR Flower is the main pet here, and those are incredibly hard to trade off fairly. The BEG goes for a Non, or maybe a tad more, whereas your pets (demand wise) barely add up to the UR Foal. Rarity isn't so much a factor in this one because you asked for a BEG. I'm not surprised they canceled, BEGs are easy to trade off, and some of your pets aren't c;