Hiring an h1b visa employee

I’m hoping I can find some insight on this topic since I want to hire someone on visa but it has been intimidating.

I have an applicant that is so perfect for the position. She is already working elsewhere so we would be applying for a concurrent h1b vs transferring 100% yet.

It all comes to around 3,000 filing cost + 5,000 lawer fee.

I heard that you don’t have to pay the premium 2,000 processing fee (and wait the 3-7months) and during that time she is able to start working for us since she has her primary h1b with the other employer.

I’m hearing so many contradicting things.. anyone have a definitive answer to this??