Motorised home cinema projector screen

[fierydormouse]

Evening all😀
Does anyone know anything about electric motorised projector screens, for home cinema/gaming/etc?
We are moving house, and the house we are buying has a ceiling recessed motorised projector screen in the living room. The vendor has offered to sell it to us for £700. We have absolutely NO idea if this is a good deal or not! We have been told no other information about it, other than it is motorised. We've not actually even seen it, as it was hidden away in it's ceiling recess when we viewed the house (although we're hoping to have a look at it tomorrow when we go back with the surveyor).
We're reasonably keen on having it (and our 12 yo son is over the moon at the prospect) but in all honesty, we wouldn't have even thought about buying one if it wasn't already there.
Does anyone have any knowledge of these things at all!? If you've had such a thing supplied and fitted recently, I'd be really interested to hear what you paid for it...
Any advice would be hugely appreciated - TIA xxx

I've not used these in a domestic setting but I have had involvement of them at work.

They probably paid a lot to get that installed although most of that cost would likely have been in getting it installed in the ceiling rather than for the screen itself (assuming it's been done properly). I'm not sure it's worth £700 as a second-hand item. £300-£400 maybe.

The other thing you need to factor in is the projector. A good projector is expensive and it will need to be mounted somewhere. Cheap projectors are easy to find but you very much get what you pay for. Even with a good projector you need the room to be dark to get a really good image. There's a reason why it's so dark in cinemas. In a normally lit room the image will look washed-out with a good projector and close to invisible with a cheap one.

I thought you were talking about a projector in a motor home. I know I'm a bit daft.