For several years after the Sims 3 came out I largely ignored the store. I spent the free simpoints I got for registering the base game and World Adventures and downloaded any free stuff that was available but I rarely spent any money on simpoints. During that period I bought the set with the greenhouse and some of the worlds that were available as simpoint bundles but that's about all. Any set like the one the OP mentioned were basically ignored. It wasn't until they started offering various discounts that I started spending money on simpoints and those simpoints were supplemented by bonus simpoints. I don't think I was the only person who took that attitude to the store and EA must have noticed a bump in revenue from simpoints sales when they started offering discounts. Maybe that's why Sims 4 SPs are more reasonably priced because people like me said no to the store until they started offering the discounts.
As for the My First Pet sp, I really missed the Sims 3 Store when I watched the livestream. I think if it was a Sims 4 Store pack I might purchase the female hair with the highlights, the fish tank coffee table and maybe the sofas and the blinds. Then wait for when the hamster was available for separate purchase. The rest of the set, I would wait for it to come on sale and see how much Complete Your Set takes off the price.
