I paid $180.00 for a mint, 80s vintage, 10-22, about 3 months ago. If you're patient, you can still find new ones for $180-200.00. I think Academy Sports had them for this price, recently.
It does have the metal trigger housing and is in 100% mint condition. The person is on a fixed income and I wanna make sure I pay a fair price "he won't name a price just tells me to give him whatever I think is fair".
From what I've seen, they are slightly more desireable due to the metal trigger housing, but not really collectible or anything. Never seen them command a premium. If you want to be fair/nice, just give him what a new comparable base model costs, which is around $200.