Price will vary a LOT depending on where you take the stuff.

I found a place that does garage doors and little car stuff and he is cheap but not as good as other places.

I've used a place that does car parts and his prices are high but he does a lovely job.

I'd say for your beam and arms £45 cheap and up to £80 for perfect (that's them rubbing it down by hand and filling in the pitted holes and coming back like glass)