[CursedMagus]

Yeah, they're one-time use. But 50% is a great margin. I don't think you'll have to buy too many.

Not really. Single use? Only 50% chance? The odds may seem good but you can still fail and that right there is just a waste of money unless you've managed to find Blessed Elrue/Lix/Xir. That way your chances would be slightly better. But I find it unnecessary. Chances are if you know what you're doing you can go up about ten levels in one to two weeks. At level 30+ that is. Although I don't think it would take that long to hit level 40. And going up that quickly would pretty much make your weapon useless at that point then you'd have to go and enhance another weapon. I can honestly only see that being useful at level 60+.