Definitely lambskin. Caviar will be visibly pebbled, and I'm surprised the seller is labelling it as caviar since it looks nothing like it.
$3K-3.5K is pretty reasonable for that condition in the current market. It's a bit high compared to what we were seeing it at a few months ago, likely due to the recent price increases, but such is the current market. I'm even seeing vintage flaps like that be listed at around $4K now, which is a bit crazy to me.
It's lambskin. Is this a Japanese reseller? I noticed that sometimes they copy/paste their listings since they have sooo many of the same bags (Chanel must be huge in Japan) and they might forget to alter a few details.