Is £80 excessive?

[NewtonsCradle]

How much is a reasonable amount to spend on a week's worth of groceries (including toiletries and household cleaning products) for 2 adults; and nappies and formula for 1 baby?

That sounds about right.

I actually think that's somewhat cheap. I now spend £130 a week but have two children but no formula, one is in nappies but mostly reusables.

No not excessive, pretty good really.

That's quite cheap really, I spend at least £130 a week on just basics. Usually closer to £150, that's before things like alcohol etc.