The body and lens, with no rubber seal maybe $150? The thing is they are such a common part being found on all Mk2 sedans and seem to remain in good condition (got to watch the Butler lenses as they do buckle).
He might get a little more listing them on Ebay, offering international postage because they do sell well in the UK.
If you're friend is not computer savvy it makes sense why his price does not reflect market value.
I've been there, sold items too cheap but it's swings and roundabouts because I've landed some bargains too.