I know from experience that at above level 60 Muffle is insanely hard to get, I think WaterBreathing is around that level too(can't remember).........

Long story short, it took me roughly 40 two-day waits with Oengul War-Anvil in Windhelm in order to get both(18 two-day waits for Muffle, 40th cycle for WaterBreathing). I almost forgot about them.

My qeustion is how much hard is it to get at level 20, then level 1? I started searching NPC's at level 17 and got what I needed by level 24.