Should we ask landlord to pay, or is it cheeky (and up to us?)

[TennesseeDays]

We rent, have recently moved DC1 into a different bedroom.

Room has a very large velux window without a blind. We have now realised that we will need to get a blackout blind to use the room as a bedroom (was used as a study before).
I have checked and a proper velux blind is well over £100, cheaper brands are still around £80 at the least.

Would it be reasonable to ask the landlord to provide a blind, given that we will leave it behind if/when we move out, since we are very unlikely to move somewhere with the same size and type of window ? Or do we have to just suck up the cost?
(If it's relevant, other rooms were also curtainless/blindless when we moved in, but we had brought our own curtains with us anyway so it wasn't a problem).

We bought a Velux blind on eBay for about £30 a few years ago, have you looked up the model number?

My 9 year old could fit a Velux blind - it just snaps into the frame.

They are expensive though. I think there's no harm in asking.