In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
... reverse slope, you can go up a pipe size to keep the steam velocity down, and/or install drip traps on more frequent intervals than would normally be done for a forward slope. Normally, forward slope is the way to go, if it can be arranged. However, there are places where you just can't do it because of space restrictions, or with a one-pipe steam system.