250-400 is probably what I'd pay but yeah, I've seen many of them go well over a grand, look on Terry's old page
LINK :: http://grandpamarble.com/html/cac.html
I was referring to a clear based Guinea you show pictures of and the of splotches of color on the surface. the less white spots the better. Clear based Guinea's are the lowest priced.
Not Christensen, I see no tail, just drizzle, machine made IMO, I won't hazard a guess as to the actual manufacturer of the marble at this time. Someone will chime in that knows what it is, maybe @cheese will have an idea ??
These all look like clay marbles as far as I can see, probably a mixture of glazed and unglazed. Some called Bennington's and I do seed some called Chinas. You can sort these by glazed and unglazed, that'll be 99% of the battle.