My estimate was based on the $5 chip. The Tyson chip was also released at the same time, and as a boxing chip collector, I would want the set. I also believe the $25 Lewis chip had the same picture as the $5, so that is why I did not bother to get it.

The Lewis chips were numbered, so if you had a interesting # (i.e. #1, #1000, #777, etc.) it may be more valuable.

With just the one chip:
$5 = $7-$10
$25 = $25 - $35 (my experience is that few Lewis/Tyson collectors want to shell out the $25 when a $5 is available)