If you think the pistol is worth $125.00, then regardless of what "the book" says, then that's fair. I've bought stuff, then found it for a lot less a week later. No harm no foul though, it was worth it for me to have that particular one right then. If you like the gun, go for it.
That said, this is what "The book" says. It lists the RJ22 as being the absolute exact same gun as the RJ38, except for caliber. Completely identical, right down to the melting point.
The RJ22 lists for:
NIB: $165.00
Exc: $125.00
V.G.: $100.00
Good: $75.00
Fair: $50.00
Poor: - (no listing)
By the book, probably not. If you offer the seller book value for the pistol, roughly $50.00, he might get offended and think you're low balling him. Then again, if it's been sitting in a drawer for 10 years and he really just doesn't care, he might go for it. Regardless of the book, is having that particular gun, right now, worth the cost to you?