What fake items are still worth money?

There are some stamps.

Synthetic lapis lazuli. Lapis is an extremely rare gemstone and it has been counterfeited countless time. Among the types of fake lapis, synthetic lapis is the most acceptable because it still technically a lapis with the same chemical composition. And beside, people are opting to synthetic gemstone these days, for the sake of workers’ safety and environment protection.

A 45 record from the Beatles of the song Anna was a bootleg, but is valued at over $1000.