we bought a capsule and a carseat. the car seat we have is a birth to 4years one, but i liked the convenience of being able to take DD in and out of the car without disturbing her while she was little - esp given she was a winter baby. she used the capsule until she was 9kg (pretty much right on 9 months) and is now in the rearward facing position in the carseat until she hits the maximum weight for that (around 12kg).

if you're on a budget, the birth -4 carseats are the way to go for sure. they are safe (check out choice website for info on what are deemed the safest brands) and baby is just as comfy. i personally liked the convenience of the capsule as i was able to settle DD inside when we were out, rug her up with a blanket over her, and get her into the car undisturbed, take her into the house when we got home etc. it really is a personal choice. a LOT of people use just the car seat and it's fine to do!