I am certainly not a millionaire and have purchased PP from Baltia numerous times. Not within the last couple of months, however, I am on the phone with Investor Relations every so often discussing a potential buy with them and my buy group.
I can tell you that the $20,000 minimum is for NEW investors that come to Baltia. I can write them a check for $10,000 and receive shares in return. That $20,000 is for non-ACCREDITED investors only. (Those who have not purchased shares from them before)
To further answer your question, I have been able to sell PP on the open market. I did earlier this year only once along with other members of my buy group. With our gains, we purchased PP again from Baltia a few weeks later after our sale. We are holding our current positions and are actually in the process of gathering funds to potentially purchase even more.
But to clarify. You do not need to be a millionaire. You are held to a min $20,000 if you are not accredited by Baltia BEFORE they filed Form D. At least from my personal experience.
Also the PPS is determined by the current market price and what Baltia is willing to set. That doesn't mean currently they will give it away for exactly 50%. The more $$$ you give to Baltia during your buy, the closer you are able to get a 50% discount.