There's been a common theme at my real nappy demonstrations recently.
Mothers with a child already (most aged 18months+) are now looking at cloth nappies as an option because they're considering the cost of having two children in disposables.
They come wholeheartedly wanting to use cloth nappies and most don't even consider using them on the older child too. There can be huge benefits to doing this; no more nappies to buy for older child, only a small extra investment for the extra nappies required, birth to potty kits will fit both children, almost all council cash back schemes are per child not per household double claims can be made and of course the reduction in waste which with two children would be significant. Older children will benefit from potty training sooner once they feel the wetness, instead of the 'dry' feeling disposables give.
It's worth considering changing the whole family to cloth, something to think about when you're looking for your youngest!