The most important, but not obvious, point: parents, as a rule, do not usually plan stairstep children:) Well, what to do if it happened – ok, will solve one problem at a time. Costs are increasing disproportionately in such case. But they can be significantly reduced. Because there are two types of strollers for twins on the market, at least as of April 2019.
The chassis is a key point.
There are strollers that were originally designed for exactly two children.
And there are pushchairs that can be used for two children ONLY if necessary.
Uppababy Vista on the photo 
Think about it!
If you have one baby you just can use such pushchair like a regular “single-seat” which passes into all elevators and doorways and do not weight too much. But at the birth of the second baby, you just buy some additional items to YOUR already exist stroller and it turns in the stroller for the twins. At the same time, you do not have to buy another new one for stairstep children which will be significantly more expensive than that you already have.
Chassis Weight
It seems small only in the store. Therefore, 10-13 kg do not scare you there. And how wrong you were! :)
The weight of the kids is increasing every month. Both of them)) Plus clothes, toys, food, mother’s coffee in the cup holder... the weight come out well enough in total.
So the lighter the chassis is the better for you!
But there is one point. Lightweight, durable materials and designs are not cheap.
So think about the stroller to grow into...just in case :) Just to optimize your future costs. If the new addition to the family occurs suddenly and not according to the plan you will understand how the thought was bright.
The chassis weight of the “growing” strollers for comparison
UPPAbaby Vista – 8.8 kg without a basket
Easywalker Нarvey – 8.1 kg with a basket (here in details)
And this is for twins initially and forever :)
PEG-PEREGO Duette Piroet Pop-Up – 12.9 kg
