I know which one I would choose, the only upside I can see for the higher price is that her availability might be better now.
The only reason I haven't seen her so far is that she normally only works during the day which is no good for me.
Not sure that being with the agency will change her availability. There are a couple of their girls that I would like to see but haven't managed to due to their limited working times.
Having said that, Summer is available today 2pm til late according to their website. Get in there
Looking at the site, I've also just noticed that Violet Hanabi is no longer listed