Re: colt sp1
Yup...it looks like a rack grade SP1. Again, if it has the box, paperwork, etc., and it is in as good a shape as it appears in the couple photos you posted (and assuming it looks that way inside and out), I don't think that the $1k you would pay is out of line. For purposes of "flipping" it...that is your call, but I wouldn't expect to make a "ton of money" off of flipping it and it could take a while based on how high you price it, but I think it is safe to assume you'll get your money back out of it, plus a little to boot.
As for funshow pricing...that is the LAST place I would look for pricing guidance because the vast majority of pricing I see at shows is highly inflated (based some on "trade" value...based some on people overvaluing their collection items without thought of the market...i.e. - unless you live in a ban state or REALLY want one, why would someone spend $1500 on an SP1 when $1500-$1800 buys one HELL of a modern AR with vastly more than any SP1 could ever offer).