$250 or so for handguns.

A premium for the assault rifles considering, if Feinstein's bill passes, they won't be able to buy another.

Basically, enough to make people really consider it, and more than the gun nutters would be able to offer on such a large scale. But not enough, that would entice the seller to turn around and buy another.

is way under market for anything but .22 cal semi-autos. The ar-15 used in the CT shooting would be $1-$1.5k new, maybe $200 or so less used, depending on options/maker etc.

So, I suppose many will be turned in for the credit by many that have had a change of heart concerning weapons over the event of the last week and don't want them in anyone else's hands either.

For example, grocery stores have participated in gun buybacks around here by providing gift cards.

These incentives, plus the disincentives placed on getting ammunition to actually use these weapons that Feinstein is proposing, PLUS greater personal liability should these weapons be stolen and used in a crime, might just be enough to get some of those who purchased them for bragging rights and don't truly appreciate the sport, to give them up.

their extra weapons. Although, as with the first AWB, the market price of pre-ban weapons would probably skyrocket, necessitating increased funding.
Ammo is an interesting idea although is easily made at home with very little equipment/cost.

The personal responsibility/liability issue could be a bit tricky, as GENERALLY, an intervening criminal act (stealing the item used in a crime) absolves the true owner of the object used (say a car) in a further criminal act. That is why it is different if someone steals your car while drunk and crashes into someone (no owner liability) and if you should have reasonably know that the person was drunk and you toss them the keys (owner has liability). Maybe a 'negligent storage' crime? But that begs the question what is proper storage? Considering that the Heller decision already found that DC gould not require that weapons be locked away/inoperable (as that would undermine the constitutionally protected right to self defense in one's home) at least when one was at that location, I am not sure how that would play out. Maybe gun safe? Does it need to be bolted to the floor? What about renters who can't bolt things to the floor? Hmmmm...... need to think this one through.

Good thoughts though and interesting discussion.

...and actually pass Congress.

I think this could.