I have two guns that might fill the bill, but I need $250 for either, plus $30 shipping. Both are in excellent condition.

One is a Mossberg 500 that will take a 3" magnum and has two barrels. For an extra $35, I'll throw in the synthetic pistol grip stock and forearm that fit it.

The other is a pristine Winchester 1300 with black synthetic stock. It, too, will take a 3" mag and has two barrels.

I prefer an 870 to either the Mossberg or the Winchester, but you'd be hard-pressed to get one for that price with two barrels. You can look at either of these guns on Gunbroker.com, my screen name there is USMC1978.