Cheryl has a great blog post about the 223 (scroll down).
http://dragonpoodle.blogspot.com/201...e-singers.html
She says it is easy for a beginner to use. A basic zig zag machine with blind-stitch added. It is very heavy but that is true of many vintage machines. I have bid on several and even won one 223 on shopgoodwill but the one I won they lost in the wherehouse! I have seen them occasionally on craigslist but I have other zigzag machines that I really like (singer 237, several Kenmore 158.xxx models) so not looking for one anymore. But it sounds like a good option if you can try it out, the price is reasonable ($50-75), and the weight is manageable.
Edit: I just looked at the ad link. I noticed the cabinet looks good, but the top is usually the worst part and I didn't see it closed. The paint is chipped all along the front of the machine bed. If that is not going to annoy your friend, then offer less because of that. And why is the sewing light laying on the bed instead of in the back? Probably not a hard fix, but reason to offer less. It's dirty and no mention of manual (easy to find as a download) or attachments (takes standard low shank). All reasons to offer much less than he is asking.