Rich,

I don't have my price guide handy, but here's what I know about the two chips.

The Riverview chip with the overstamp is pretty common. These came out awhile back and are around $10.

The Little Turf $5 chip is a recent find (within the last year) and were found in limited numbers. I don't remember what I priced these at (probably $70-100). One thing I did notice is that it looks as if the hot stamp has been filled in with a marker. This will decrease the value of the chip.

Ed