"If I get this gun and plan to take it to the range (100 yards) occasionally ….. what mid-price-range scope or other optic should I consider?"
For this specific purpose, ANY scope will be fine. I like the VORTEX Crossfire 2-7x32 because it's more compact and offers good optical clarity. Plenty of magnification for any use I have.
Yes, there are more specific use scopes that have become very popular due to the '3 gunners' but most of these have features no needed for your stated purpose. One of these that I like is the VORTEX Crossfire 1-4 V-Brite model. Crosshair with a pinpoint illumination in the center when turned on. The illuminated center dot doesn't overwhelm the sight picture like a fully illuminated crosshair may do.
The downside of these 'Tacticool' scopes is the weight since many/most weigh over a pound plus the mount. I have 1/2 dozen of these '3 gunner' scopes from 4 different brands (USA branded and/or pure Chinesium) and none really offer a great advantage over a moderately price 2-7x or 4x scope in actual use.
"PRISM" scopes tend to be eye relief sensitive and so far, I've not found one in my price range that doesn't overhang the rear of the upper. At that point, I'll just use a common scope and get a wider field of view.