I do annealing for $0.10/case plus shipping. High power or BPCs. Work is done on my the Bench-Source machine. Turn-around time is a day or two. Must be decapped and clean. Or, I can do that as well (Thumbler tumbler - they do not come out shiny but they do come out clean) for an additional $0.15/case.

Guns - the call to anneal 45's (Colt?) is yours but:
* I shoot Starline brass exclusively, hardest of the other vendor's Colts with BP
* I'm guessing but over the years, probably 20,000 Starline BP rounds shot
* I have never or had to anneal any of the Starlines

You might want to anneal them yourself, if you desire.  For the 150 cases, would take less than 45 minutes.
* Deprimed cleaned cases 
* Needle nose priers, one end in the primer hole and other end gripping the rim
* Propane torch - heating the case from the distance the bullet will be seated to the mouth ... twist the case with the flame until the brass turns a bluish/green color (temperature is 625-650).  If case glows red - you over annealed
* Drop the case on a cotton towel to air cool - do the next case and all until done

Have to ask you ... Why do you believe 45 Colts have to be annealed?