You need to take into account so much when buying a pram - and be honest with yourself about what you need.
I speak from experience - we have a very small house with steps up to it. I thought that wouldn't make much difference. In reality it means we never used the pram after 4 months and went to a much lighter and easier buggy, as I was sick of lugging a baby and a pram up the steps, and also didn't like dancing round a travel system every time I wanted a cup of tea.
So - ask yourself:
Where will the pram live? Honestly? Do you have a hallway? You won't want it in your living room or (as ours was) plonked in the kitchen. If you think it'll live in the car - is that feasible? Who'll be using the car most days? Figure out where it'll go, and measure up!
Do you go off-road much? If you're into the outdoors, either get something appropriate or accept you'll be using a sling or back carrier most of the time. We spend every weekend out walking, hence another reason the pram became redundant. The baby Bjorn,though, was used day in, day out.
Ditto for public transport. If you're on and off trains and buses most days, forget a big pram. You won't use it. I've been that person trying to dismantle a travel system with one hand, with a screaming baby under my arm, getting on a train in Manchester Piccadilly at rush hour. Never. Again.
If you do go for a big travel system, get one that you can realistically dismantle one-handed and pop in a car. On your own. While juggling car keys and a baby. Practise! If it's a bit heavy or too faffy, get something else.
Think about if you plan on having more than one baby and if so, plan ahead. Yes, plans may not work out, but unless you're loaded you don't want to buy an expensive travel system this year and then a double buggy in a year's time.
I'm sure I've missed something, but hopefully that helps...