Occasionally the list of characters that can use these bespokes is increased (e.g. if a new character in the same theme is released) so I tend to keep a spare or two handy but that's it. The exceptions are Paranoia and Sinister Solstice which are so useful I keep a couple of extra spares.

Other than that the only use for them is to sell them or upgrade ones you currently have from T1 to T2 etc.