the fewer the miles on the odometer is certainly better. the condition of the machine itself is indeed far more important than what the readings tell you. and as you've mentioned, since the 110 model is older, it's definitely "older" so if i were to choose between the 110 and the 125, again, depending on the mileage and machine condition, i'd get the 125. about the price? well that depends greatly on where you're gonna get your bike. if you were to find a 2nd hand bike from honda dealer or motortrade and the like.. they'd probably mark up the price around 33k-45k!! pretty expensive imo because if you can buy it from someone you know or from a personal seller, you could hopefully get something that is cheaper.
ps: i sold my xrm 110 fully setup; semi full race: mags, alloy swing arm, quick throttle, open pipe and other pretty darn good accessories and body kit that came from thailand, not china for only 20k. but then again, i was really needing cash back then to get my new bike. so most people i know said that it was a giveaway price.