Define fancy bike?
If he really has a good expensive bike, he may not be happy with a $150 bike from amazon. I never appreciated that until I actually had a cr@ppy bike to use - Yuck- and I'm only 'commuting' < .5mi!
Finding a good used bike would be a much better compromise. Bike fit isnt by height alone - leg vs torso length also plays a part. How tall is 'shorter ds' vs dh? The upright geometry of a beach cruiser might be more forgiving than other styles in terms of size but maybe not.
dd1 10/05
dd2 11/09
and ... a mini poodle!