The best way is to ask them - my experience has been that people tend to be fairly comfortable discussing per share prices.
I used to work at Palantir. If I want to know what my shares are worth, GSV (which is publicly traded) owns Palantir common and preferred shares (as well as shares in several other private companies) and reports a fair market value in their public 10-Q and 10-K filings. This is useful as a baseline sanity check. There are also enough interested buyers that it's feasible to get multiple price quotes.
I used to work at Palantir. If I want to know what my shares are worth, GSV (which is publicly traded) owns Palantir common and preferred shares (as well as shares in several other private companies) and reports a fair market value in their public 10-Q and 10-K filings. This is useful as a baseline sanity check. There are also enough interested buyers that it's feasible to get multiple price quotes.