Topic

If you have the skills to break the car you have the skills to repair it as well

Another one with seat belt mount excessively corroded. That's impossible. The seat belt mounts are under the T bar (impossible to see) and the seat. If they're saying the sill is corroded then that is a reason for rejection, but they have chosen the wrong category. Even then, find someone who can weld and that'll cost maybe £150 to fix.

Agree with the others. You're being ripped off. I suspect the car is fixable for a lot less than half that. Nearer £500 as an expensive estimate. Probably less.

Washers... - put a needle into each of the washer jet nozzle and gently rotate it around the edge of the jets. Then re-adjust to point at the screen. Make sure the bottle is topped up. Cost £0

Lights out - as it's both lights - check your fuses... If the fuse has gone, replace, then check the brakes. The lights will probably work... Check the other circuits on the fuse (it will be labelled up) don't blow the fuse and you're good. If they do blow the fuse (I think it's the reverse lights), have the circuit tested if it's essential (reverse lights aren't) or disabled if it isn't (reverse lights is a matter of disconnecting 2 wires and taping up the connectors) EDIT: the other thought is the boot loom. A common problem with our cars and easily fixed.

Get the back end of the car jacked up and supported on stands.. inspect the brake pipe leading from the tee piece to the driver's side. use a fine wire brush to remove surface corrosion, then coat with a layer of grease. cost (the grease)

If the pipe is severely corroded, then it will need to be replaced, but that should be doable for £150 ish. (You could probably get a good used one from MGFnTFbitz and have that fitted)

fit new front brake discs and pads (service items) £75 fitted.

Anti roll bars are likely to be the bushes again £75 fitted.

I totally agree with the above.
I further agree that it is impossible for a corroded sill to effect the seat belt anchorage. That is just sheer laziness or ignorance. As is mentioned above the seat belt reel anchorage is behind the seat under the T Bar, nowhere near the sills. The other anchorage is on the seat frame.
In other cars he would have a point, where the seat belt is anchored near the floor usually under the B pillar, right next to the sills.
My repair estimate would be £300 max!