Scarlet is one of the best RM made IMO... I own it both in MAM and Nikki.. I personally LOVE it. I was searching for the perfect red bag until I bought the scarlet RM... The distress leather is just so special. Also to me this bag is special because Scarlett Johanson owned this bag and donated to charity.. so I can always tell me friend SJ has the exact same bag.. lol.. yeah.. i know that's a little silly...
To answer your question, it is on ebay for cheap because it was available during RM sample sale.. so people paid like $275 for the bag.. probably either flipping it on ebay or just decided they don't want it..
To me, ebay's price does not reflect how beautiful the bag is IRL.. it might reflect how popular or rare it is..
There are so much bags went for skyrocking price (e.g. $500 to $600+ even for used), but some of those are only because they were earlier RM bags that can no longer be found it stores... so people perceive them as "rare".. I think it is sort of silly..