Sanctum fans - how do you feel the rooms revealed / merchant rush strats compare?

I've had a great time with sanctum runs, but the prices on 2 room/2 extra merch choices relics are high enough that I can't go and just buy a ton and not care if it doesn't work. I've picked up a few 1-room revealed relics so have been drifting in that direction, but I'm still wondering about investing in better relics.

How many of you have played both strats? How did you feel they compared with proper investment?