as much as a buyer is willing to pay.
Generally, for such extensions, not much, not much at all.
for .ws/.in/ and maybe .cc, you might get an 'ok' reseller price for a strong keyword for developers.
the exception is probably .in which in the long run might have some value, but for now, any money being made (and it is being made) is because of speculation. This, can, and might, shring at any given time