They need to send you the 350.
Photography
A place to politely discuss the tools, technique and culture of photography.
This is not a good place to simply share cool photos/videos or promote your own work and projects, but rather a place to discuss photography as an art and post things that would be of interest to other photographers.
If you are on Windows, you can use the free program Tinta to cull many of the images. Set the thumbnail size to one of the large options and delete the ones you don’t like with the delete key.
It's not so much the technology here, but the selection. As a photographer, I would 100% not expect the retoucher to be on the same creative page as me, unless the photographer really doesn't care that much. I've cut down portrait raw shoots by a factor of 10, it's just a normal thing I budget into the quote.
Sorry, I misunderstood the issue.
There isn't a set or average amount of time. It depends on how similar the photos are, what issues each has, etc.
Charge them by the hour. Make sure they provide detailed criteria for which ones they want.
You should absolutely charge for that. That would take me a few days to go through