If you LOVE it, then consider it.
If you like the bow, then it could be worth considering. If you don't like it, then crack or no crack, it isn't a deal.
If the bow survives the bending process and becomes a bow without further problems, and the maker stands behind his repair, you should be ok. Usually G2 epoxy or a similar glue formulated for bow woods will be used and depending on the extent of the crack, some new wood might be added as well. The glues available now are fantastic, and often the repair can be stronger than the original wood. I had the pleasure of working on a Sartory that had been broken in half more than 20 years ago and glued, and it has survived under daily use to this day with no signs of trouble. Pay particular attention to the camber (the bend in the bow) and make sure that it is flawless, and the stick is perfectly straight. With a repair like this, you cannot make adjustments to the camber (at least in the area around the break) for the remaining life of the bow.
If you intend to have the bow for the rest of your career, it could be a good option. If you want to sell it down the road for one reason or another, broken bows (even those by famous French masters) typically lose anywhere from 40-90% of their resale value.
If the maker is willing to finish the bow and let you play it without pressure to purchase it, then you've got nothing to lose. Try the bow. If it really is "the one", hands down better than anything else you can possibly afford, and you can see yourself playing it for the rest of your career, go for it. If you aren't completely in love with it, could see yourself trying to sell it down the road, and/or aren't in a huge rush to upgrade, there will be other bows that come along.