First on think the cost is even lesss.
As the bottle is reusable the potion is actually 50 sips and 10gp PER SIP.
Secondly on a quick tour around all of the usual herb sources I found NO kathuska.
I was therefore unable to check the cost but availability seems poor.
Isaac you do however make a very valid point (albeit unintentionally) there are certain requirements where herbs (subject to availability) are the best and cheapest way of getting the cure/protection you want.
Potions have made players lazy and the herb picking professions uninspired to pick, preapre and put their goods up for sale. Hopefully this will change to their benefit.
Again, to those who think the pricing is too much respond to these points with sensible and constructive logical criticism and we will listen.