search the auction house results - Antiquorum and Christie's are great sources - as is Sotheby's.
I believe it is based on a JLC ebauche. This is not uncommon, although they are moving to more all in-house movements.
I really like the look of it, although you really want to get an authentic VC bracelet or strap on there.
Do you know its history? Has it been restored, serviced, etc?
If you just bought the watch its value is what you paid:-) Cal 498 is based on a JLC ebauche
I am guessing we can guess exactly what he paid! Or someone seems to have about a month ago.
No price is too high for a work of art.