I got this 640 around Thanksgiving for $375, box and such. It's stainless so I have trouble with "% condition." I figure it's worth that. Don't know about L frames, haven't owned one in about 10 years. Joe
If it came down to a choice between the two, I'd take the 640 no-dash. But then that's been my EDC for over ten years, and I love those little guns. Both would probably fetch a good resale price in today's insane market, but from what I'm seeing the concealable pieces are very hot right now.
I bought a very clean 686-5 with 4" barrel without box and papers for $600 within the last year.
A new 686-6 with lock is going to be $700+. I would prefer the Dash 5 myself. After the first trip to the range both will be valued similarly as used guns.
The 640 is also very desirable.
It will be worth atleast $400 in the condition you describe. It might even go $450.
Considering the current price jumps and panic buying, they very well could sell higher on the market than what I listed.