The draft at the moment just has a duration of concentration. Anyway, I'd go for 1 hr/level.
OK, what do we think about the cost of the normal tabernacle focus? I'd think to keep it relatively low (maybe a few 100 gp), but I'm willing to be convinced one way or the other.
Let's say 750 gp. Seems like a reasonable midpoint we both are ok with.
These critters aren't all that nasty. After all, they only suck energy from bad guys.
The normal tabernacle should be made of ?? Specially treated wood, precious metals?
How about this?
Focus: The tabernacle, a well crafted ritual chest, constructed by master crafters. The tabernacle never costs less than 750 gp and is approximately 5 ft long, 3 ft wide, and 4 ft tall.