You're talking about skipping an infant seat and going straight a convertible. It can be done but I would say most mothers would argue that the infant seat is very useful. You can take the entire seat out and bring it with you if the baby is sleeping. Otherwise you have to remove them from the seat and either wear them (and many people do) or put them in a stroller and sometimes neither option is perfect. Personally, I'm team infant seat all the way
The seat I have in mind is designed for 560 lbs in order to save money, but I'm realizing that it does not sound very convenient to move a newborn over and over. Has anyone had luck with a Moses basket?
I successfully did the convertible with my newborn son to save $$. I chose the My Ride 65 from Graco. In the first few months I simply didn't take him with me shopping. (sounds crazy but it worked for us) I also have a City mini Stroller. When he was about 2.5 mos old we used the stroller for the first time--reclined all the way back. I never regretted not having an infant carrier. As my son got older, I would pad the grocery cart seat with blankets and prop him in there sideways (I always stood right in front of him, never stepping away.) It wasn't bad. When we went out to eat, my husband or I would hold him until he was big enough to sit in a high chair. The time went very quickly and I never missed it. My MOM says if I have another kid she wants to get one because she thought it was a pain in the A$$! haha
Team buy an infant seat all the way. I'm big on baby wearing and did it a lot but there are times and places it's just not convient, namely eatting out when they are under 6 months and can't reliably sit in a high chair. You need somewhere to put them so you can eat and it's nice to have your hands. Not to mention dragging noodely newborns in and out of a convertible just wouldnt be fun. Get the infant seat for now and then do more research on convertibles when your LO is 4-5 months and you have a better idea of how quickly they are growing.
Re: all in one car seats