No one needs to drop a grand on this bike. Someone just needs access to a machine shop that's willing to work on a vespa to drill out the old bolt. There is absolutely no reason to replace the case, Vespa Boston just didn't have the tools. Vespa Motorsports in San Diego already agreed to drill it out for me so either I'll pay them $150 to do it or someone else will.
So the potential buyer was turned off by the bolt issue? Honestly, the way that scooter sits it is a parts bike. If someone pays you 2k, and ends up needing to drop another grand on a fix that may or may not be permanent, they have way over paid for that bike. Drop the price to $700 if you want serious buyers.
Once the bolt is out, the bike is good to go.
However, I do agree that $2k is too much. $700 is appropriate for a parts-only bike, but this is a registered driveable vehicle so it should be priced as a salvage vehicle would, which seems to be around $1200-$1500