Of significance to the 1998 Ferrari 550 records, this prototype Mercielago had 100 hp advantage and a litre greater displacement in the engine.
In regards to 550WSR limited edition valuation, this actual record-beating prototype car's sale at 95,200 GBP (about $150,000) with 117,200 km driven: shows little premium is accorded by collectors to actual record setting cars of this type and the 550's from Ferrari.
One could say of these expensive cars, "So what? The do what they're designed to do. That's why they're so expensive to begin with."