You can't actually attribute increased demand due to an update to price manipulating. There happen to be hundreds, if not thousands, of players just like you, trying to buy their 89 herblore and 95 prayer. Price manipulations drive prices up, but the same forces of increased demand turn into increased supply and shoot the prices right back down. Long run demand, however, brings the prices up, something not brought about by merchanting clans. Personally, I just bought 27k dragon bones for 95 prayer. Am I happy that I waited until now? Of course not. However, as more and more people try to pursue a higher prayer level, I recognize that prices will slowly increase, so I'm getting it while I still can. I would recommend just gritting your teeth, making the money, and buying the levels you want, because, if trends continue, prices for both prayer and herblore will continue to rise.