What is this Thomas Set?

Yes, I do agree with you about the market value.

And yes, finding a very rare item new requires patience and a decent amount of money in your pocket depending if the seller is listing it for its retail price or from a starting bid.

Like, I had a bidding war this December for a new in box "Toad and Trucks", the seller put the starting price at $10 but it went up to $78 which I ended up paying because I think it was worth it, it is unlikely to come across this item new in the box while Sir Handel can easily be found new in box (T-33). I guess sellers do this to make more money and to make the items more sought after because of their price.

The crazy $300-$500 dollar Sir Handel that commands this price is a Bnib original first release Japanese issue pagackaging of the Plarail model. (The same as the ones you just scored) Western market packaging Tomy/Hit English versions do not.