I would say the ivory chip would be worth about $1,000. If you had a clay Robert E Lee chip it would depend.

Assuming there was one or couple of these chips found I would value a hot stamp at $50. If it was a crest and seal chip (smooth mold chip with a printed (or litho), I would value it at $400 to $500

Of course everything depends on who collects what. There happens to be several ivory ciollectors that would pay $1000 or more for scarce ivory. If the Robert E Lee was a Vegas casino, the chip would be in the mid 5 figures.

I don't know who would collect Robt E Lee chips. I would collect it only if it was a crest and seal.

The answers depends on who wants the chip.