A baby/ activity mat! The most basic and functional item every baby must have, and easy on your pocket too :) We got ours as a gift, and Hayaa loved it. The first few months, she would just play with it, lying on her back.. then she started to pull the objects with her hand, and then i removed the rods and the little toys, and would use it for her tummy time. When she began to sit up, i would use it as her toy mat. She loved it, and i loved it because it was so useful! :)
3-6 + months
The swing
This is pretty pricey, but hayaa needed it and it was worth getting it. The only thing I regret is not getting it sooner. Why did we need it? It was the only thing Hayaa would fall asleep in if i wasn't around.. so for my mother-in-law, it was really useful to put Hayaa to bed on days when my hubby and I would go out, or even if i had to run an errand and hayaa was tired. It really helped when I started school too (when hayaa was 8 months) and even today (11 + months masha'Allah, she still uses it).
6-8 + months
Space saver high chair
Our swing is fisher price 4-in-1 that converts into a highchair, but while we're so addicted to using the swing, we can't convert it into a highchair. Regardless, a huge high chair doesn't even fit into our space. This was such a better option. We got ours from walmart for about $40, and it wasn't on sale at that time. If you're a fan of the bigger one and have space for it, for the thrifter, the ikea one is nice and if you're willing to pay the extra $, there are some really nice high chairs available (i liked boon flairs highchair).
So back to my need for a space saver, I was getting so tired of having hayaa either in my lap or near my feet everytime hubby and i sat for dinner, we needed this.. as an added bonus, I would leave hayaa in it when i'd cook and she'd sit on it for the while, play with her toys and eat her snacks.
Activity center
After getting Hayaa a swing, i didn't want to buy a new activity center for her, especially because I wasn't sure how much she'd use it. She didn't really use her bouncer much and that was a disappointment, so I wanted to play it safe and get her a used one. Alhamdulillah we found a nice one from a family friend, and to my surprise, Hayaa did play with it a lot. She didn't like it early on (4-6 months) but at 8 months, she spent much of her time in it. Now she occasionally uses it. We have to force her to go in, but once she's inside, she plays for quite sometime.
Because this is sitting in my living room, and she does play iwth it quite a bit, I did regret not buying her a new one. I think if i could do it again, I would do the opposite and get her a used swing and new activity center.. because it's used so much, for playing, eating, jumping etc. and it sits in our living room.. so yeah.. but for Hayuu, since she's gonna grow out of it soon, ours will do :)