I never had stuff packs for Sims 2 or 3. Only expansions.
For Sims 4 I am behind on most of the packs. I have all the EPs, but all have been brought at a discount. I have parenting which I did buy full price on release. And vampires and spa day which I recently brought in the bundle with the stuff packs. (Basically I paid GP price for it and effectively got the two SPs free!) I really think stuff packs are overpriced for what you get so I pick them up on sale, if at all. I think I got spooky stuff last Halloween when it was literally like £3! And I brought romantic garden at valentines for about £5.
Basically I'm not fussed about having them all, all of the time. Just recently though, now I've seen how much good value those bundles are in certain places I am becoming more of a 'collector'. Part of me wants them all so I have the collection, not even so much because I will play them all... Which is bad!
Edit to add: I do have a house to run and a toddler in real life that eat into my funds something crazy so I have to spend my money wisely too.. bundles work out way cheaper. So if I ever changed my mind on wanting something else then I have already saved my money in my eyes! Also my hubby is a gamer too so he can't complain at me buying games when it's what he does too!