I usually don't edit the ad when the price changes...instead, I just create a new variation and pause the old one. That way, if the price hops around between a few different values all I have to do is choose which variation is active.
(I don't have a large number of ads that include the price, so I haven't needed to automate the process and I do it manually for now.)
the results of the campaign were huge! we had ctrs of 15%+ on each of the dynamically created ads, and also our ads were approved rather instantaneously, they started showing almost as soon as it was updated. we managed to drive amazing amounts of traffic through this dynamic ad campaign - more than 80,000 visitors on a single day. Quality score was also very high - im saying this, because our ad was always on number 1 position with an average cpc which was among the lowest we have ever seen among our campaigns.
we are in the process of applying the same concept to dynamic price insertion also, quite sure we will see great results on a dynamic price campaign too...