That's definitely an A35, taller than the A25 but without the outboard aperiodic vent slot. It's a double-chamber box with the aperiodic vent INSIDE, so it has better bass output than the A25. Great speaker.
As far as value- I'd say it might be worth up to $200 for the pair, but probably not $400. There's too many of these type speakers around (A25s, A35s and A40s) for sale, for someone to really realistically ask that kind of money. I'd personally be inclined to suggest offering $150 for the pair, if they're in as good of shape as they seem to be...
Regards,
Gordon.