A couple of comments/rebuttals...
First of all, Bianchi aren't a top-notch holster in my book...but would definitely take one over a Don Hume. Don Hume's products are cheap leather that LOOK ok. He stains the leather with a spray, for crying out loud (it'll rub off on you if moist...believe me).
Sparks and Rosen holsters have high-quality leather and handwork in them...especially the boning. One of the reasons they are more expensive is that they HAVE to use high-quality leather to cut it so thin yet retain strength. It's cut thin because there will usually be a steel reinforcement in the mouth area that the leather covers.
I LOVE my Sparks VersaMax II holster for the .45...in my opinion, the most comfortable IWB holster on the market. My father has several other Sparks holsters for his .45 and they are all top-notch as well. Rosen makes AWESOME stuff too, and Kramer has a good reputation.
SPEND THE MONEY ON A GOOD HOLSTER...you'll be glad you did. You can always make more money tomorrow.