Yes, I got mine at $349 with free shipping. 10.5" CHF upper, MPI marked premium bolt, everything was basic mil-spec. Item number 516445822.
However, I would not let that keep me from buying the item you want now. The price they were in the past does not guarantee the price they will be in the future. I don't expect to see prices that low again till after the pandemic cools off and after trump 2020.