First off, this is my favorite era of Mopar car's and I have been looking at 65 Dodges for years. You do not see too many Monaco's in this condition. I am impressed the basket weave trim on the rear seats looks 100% factory; everything is clean. At this price, every light bulb, option and A/C should work like new. It is optioned similar to a Chrysler 300 letter series back in the day without the leather seats and tach in the console.
The $22,500 CAN price coverts to $18,265 in USD. Please note the condition of this car appears to be on the line from moving past the driver category to trailer queen. Also at this price point, it should/could have had power windows.
The question is, what do you want to do with it?
I would want to drive it, and therefore would go as high $17,250 Canadian [$14,000 USD] . As a trailer queen, it is reasonable. With the way old cars prices are going, you would have to be comfortable paying that price to know there is a 98% probability you would not get close to this if you re-sell it.
As for the red paint, check out the plastic red flags on the trash cans. He has a red color marking compulsion. The paint is also on the manual vent levers in the interior on the dash. Psychology 101 tells me the seller is a very intense, organized guy, has an eye for detail, and is not likely to budge on the price.
In summary - if you want to have it parked in your garage and keep it covered, and occasionally wipe it down with a diaper, the $22,250 CAN price is appropriate. But it will deteriorate from age and never be as valuable-desired as other Mopar's.
I would drive the hell out of it and enjoy it, it is a very fun car with a great look, be OK with letting it get used, but I would not feel comfortable paying that price.
I hope this helps. If was me, I would sell the car I have now and buy this one if it was in the $14,000 USD range.
Let us know how it turns out. Good luck. Steve