Even with the 83b, you'd still have to pay taxes on the current value. This is practical if the stock still has negligible value (i.e. you joined pre-funding), but otherwise you face being taxed on monopoly money.
More likely, the company might give away shares to an employee in lieu of salary, but then the employee has to pay taxes on the value.
In other words, there's no way to obtain stock in a private company without facing some kind of expense. You're either paying money directly for shares, or paying taxes on the gift of shares.
The only way to avoid any of this is:
1) Be there at the very beginning, when shares have negligible value and can be bought easily. OR 2) Be granted stock options instead of real stock.