It's really just a judgement call. If you're gonna need to have a great one to ride, and considering the cost of restoration, hassles with French threading, 27 inch tire limited selection, potential loss of seatpost, possibility of trashed hub bearing cups (integral with hub shell!!!), or need for original chrome Rigida rims, and having to score a good Ideale saddle, a resto can easily soar up that high. If you just want one that can be made to work so you can sample French genius and the behavior of a frame geometry dating back to perhaps the late '40s, you can go the cheap "flipper cast-off" route, and do a local flipper a favor by getting unsalable junk out of his garage.

27 inch tires are available, BTW, as are correctly sized alloy rims. You really can make a nice modern set of 27 inch wheels for these bikes.

Bottom line: if your bikes all become money pits anyway, buy this one, it will be cheaper - an investment, not a money pit.