Title pretty much says it all.  Will the sunset have any effect on the price of AK type rifles?

Yes and no...rare stuff like the Steyr Maadi, Hungarian Pre bans...Galils, Valmets, Polytech Legends,  those are golden regardless what happens. However, I can see prices on run of the mill pre bans like fixed stock Norincos going down, because, let's face it...some are decent, some are nicely finished, but they are nowhere worth 800-1000 except for the '89 and '94 bans. Now that we lost '94, you can build anything you want here...so the imports will take a hit, unless they are rare and very well made IMHO.

Some, but not much.
The import ban has more of an effect than the AWB on AKs and other weapons from over seas.

What is a decent AK type to use as a trunk gun, and how much should I pay?

Quoted: Some, but not much. The import ban has more of an effect than the AWB on AKs and other weapons from over seas.

Gunslinger hit the nail right on the head.

Get a ROMY,about 375.00

Quoted: What is a decent AK type to use as a trunk gun, and how much should I pay?

If you can live with a 10-round proprietary plastic magazine, the Saiga "Sporter" is a hell of a deal (around $170 for the 7.62 x 39 version). It's a gen-u-ine Kalishnikov, except that the trigger and stock have been altered to replace the usual pistol grip with a conventional-style rifle stock. These changes allow it to be imported without any alterations (which helps keep the cost down). Very reliable, and decently accurate (for an AK). It ain't purdy, but it'll get the job done every time (and can be converted to a pistol-grip/hi-cap AK whenever you feel like doing it).