Well, the time period involved is so vast that it would be disingenuous to give a number without context of which city-state and in what era. Regardless, it's safe to say, they did not earn very much. It isn't until the modern day that actors were compensated well and even then, only a handful can afford to live solely on their performance career without assistance from a wealthy patron.

For instance, a single drachma (usually a silver coin) could range from the equivalent of $1 to $100 depending upon the power of the city-state (if it pays/receives tribute from other cities) and other factors (war, famine, plague, weather affecting trade, etc). As well as reasons like, which city-state minted the coin; if it was silver, bronze, or gold; and what percent of those metals were in the coin. Generally, speaking, you might pay more to live in Athens than in a smaller, poorer polis, like Sicyon. Equivalent to how the average New Yorkers or Londoners earn more money on average than the rest of their country, but their rent is too damn high in relation.

Because of this incredible complexity, there's no easy answer and we historians fight over what the "average wage" was for anybody. Soldiers? Farmers? Do we use Xenophon's account or Thucydides or some combination?

tl;dr: Money is a complex issue, but the majority of actors and playwrights have always lived on the verge of starvation in any age of European History. Unless they have some other source of income: patrons? trust-fund?

I hope this was helpful and/or entertaining and/or thought provoking.