If you're just going for a canned pheasant /quail hunt I'd buy something you'd use to shoot skeet and sporting clays. Then at least you have a use for it after. A light gun really only matters if you are carrying all day for several days. I would have no problem hunting with an 8 pound gun for a day, in this type of hunt that is not in heavy cover.
That said-if you are going to get into it and hunt wild birds seriously lighter is better. I hunt grouse about 30 days a year, multi day hunts in maine, over pretty rough terrain. Heavy cover that means a lot of one handed carrying pushing through brush- which is where the light gun helps a lot. All my upland guns are side by side 16ga that weigh 5.75-6.2 pounds. These are not guns you want to shot a round of skeet with. All have 28" or 30" barrels. I find I shoot so much better with longer barrels, and even in heavy cover the extra 2 or 4 inches is noticeable to me.
So - infrequent one day canned bird hunts I'd get an over under 12 ga with 30" tubes. Browning or Beretta, but Fabarms make a pretty nice gun too. This is a gun you can use for other things. You can get these new sub $2500
Serious about bird hunting and need something lighter? That's when I'd look into a 20ga, which with modern guns will still be about 6.5# . I'd still get 28" tubes.
I'm not a big fans of the cheaper Turkish guns - sure they cost half as much as a browning or Beretta, but, you get what you pay for. I'd go used if I were in a budget. As I said Fabarms is making some nice guns as well and I would not hesitate to buy one.
This is all assuming you want a Modern gun. Every gun I hunt birds with is a Pre- 1930 side by side with the oldest being from 1894. But that's a whole other thing.