A seller might never have sold a fake and in fact may never had done anything wrong at all yet still have received undeserved neg(s).
There are also sellers who have 100% feedback who have sold fakes and either never got caught, buyers never knew they got a fake or if confronted, seller was apologetic and issued full refund.
Feedback doesn't always give a true picture of the seller's history, honesty or dishonesty.
OTOH, there are many large sellers who are either careless or who have knowingly or unknowingly listed and sold fakes. Since it's a seller's responsibility to know that items are authentic before listing, I'm less likely to close my eyes to numerous instances of fakes. After the first confrontation, the seller should realize that she may not know as much as she thinks she should and all subsequent items should be checked.
I can think of several (supposedly reputable) sellers with a history and feedback you describe and personally, I think I'd avoid them. That's just me.
If you think it's too good to be true and want to go for it, use a c.c. to fund the payment but don't be surprised if it turns out to be less than you expected.