I've 2 boys and one on the way.
Our car seats were damaged in a house move so they need to be replaced.
New baby will be in a bucket baby seat .
My oldest is 7 years old and was in an advansafix but now seems to be too tall for the seat even though he only weighs 17kg 
My youngest is 4.5 years old was in a BeSafe Izi Plus but he is already around 18.5kg and is tall .
Would you invest in another ERF for the younger child ? I'm not sure I would get long use out of another ERF with his height and weight.
Or would you get both boys boosters now ?
I'm nervous about using a booster after ERF but I also can't afford to keep replacing seats if they outgrow them too quickly 