Haven't RTFT and these have probably been mentioned.
Cafetieres. I first saw one in the wild as a young child when Mum and I were having lunch in C&A cafe around Christmas time. Our coffees were served in individual and oh so 80s red Bodum mini cafetieres. My little mind was blown. Mum never entertained getting one as there weren't too many places in 80s Belfast for you to buy ground coffee for home use. Years later she wouldn't even accept one of our spare Bodum cafetieres (OH and I had our own ones before we moved in together).
And don't start me on the little plastic swords that held the sandwiches on the platter together, so exciting and sophisticated to a child. Actually, so were sandwich platters 😃
Music lessons where you would be graded. I sang in choirs including being one of the most junior in our school's chamber choir, but would have loved piano lessons. Mum was a widow and couldn't afford them along with our other extra curricular activities. I feel ungrateful now as an adult for grumbling about this as a child, because it must have been so hard for her providing everything we needed and wanted.
Make up sets/pallets. I have loads of these now (more than I need) ranging from budget to too expensive, but to teenage me these were very desirable. The joy when I got TWO from Boots circa 1989 - one for lips and cheeks, and one for eyes!
Also perfume. Mum and I didn't share the same perfume tastes so I couldn't nick hers. I think nothing of buying perfume now, but that first bottle of Obsession in the early 90s felt like winning the lottery 😁