Compared to a standard 50 gem pull it seems worth it since for five additional FG you're guaranteed two 5* Knights and a gold bloom of each type. Worst case is getting twelve 3*/4* Knights for 15 FG compared to a standard salt roll costing 50 FG and giving 11 3*/4* Knights.
I gave all four steps a shot since I had 141 FG saved up. First step gave me a dupe Snowflake, second step gave me nothing but 4* Knights (not what I'd hoped for but 2400 bond crystals for 15 FG is acceptable), step three gave me a new 5* (Calceolaria), and step four also gave me a new 5* (Chinese Lantern).