Windscreen scratches on 240 GL (UK) incurred today

Hi Volks ( Volvo folks ),

Today during motorway driving in rain in the UK the passenger side
windscreen wiper blade ( not the arm ) of my wife's 1988 240 GL
disintegrated at its mount and became dislodged.

She was unable to stop at the time and she had to leave the wipers on in
heavy rain till she got home resulting in arced scratches to the windscreen
on the passenger side.

Even had she been able to stop she wouldn't have known to lift the wiper arm
until she got home for me to look at it.

I can feel the scratch with my fingernail and am thinking it might be am MOT
failure point when it's due.

I've looked on the web regarding windscreen polishing/repair compounds but
the consensus is, if you can feel it with your nail, it's probably a new
windscreen job.

Does anyone have an idea as to how much a new fitted windscreen will cost
and are they even still available. Preferably not at Volvo dealer prices.

What are my options.

MOT not due for a while so have time to consider.

TIA - Colin