RSU's in a company that hasn't gone public are not very liquid... not paper money, but definitely not worth face value. Take that value and cut it in half or 1/4.
You picked .5 or .25 as the multiplier. If it's still 2-5 years until a public offering, it's also quite possible for the multiplier to be closer to 1.5 or 2.
Everybody has a different assessment of how likely each outcome is, so everybody has a different expected value.
