Skoob and Dave,
Remington's price for an 1100 receiver is $273.00 checked this summer as I was contemplating building an 1100...
What I ended up with was a used, 70's vintage, 1100 Magnum Duck Gun (30" full choke VR) that was priced right at the price of the receiver--seemed no one wanted a no-steel shot, full choke gun that would not handle target loads.
But the Lego approach to shotgunning paid off...with a couple of spring replacements and some shopping for under appreciated fixed choke barrels it's quite the versitile shotgun.
With 6 million potential donor guns out there...have fun.