It's a super tough topic.
It will always depend on the value on the business. Is there a specific valuable IP? Valuable tech? Valuable team? Synergies with the company that wants to buy? Depending on these values, the price will vary.
But if we're talking purely about money/revenues, there are some basic KPI in the mainstream industry: price is your yearly gross margin X 6 or 10.
Meaning that if you're grossing 1 000 000$ revenues, with a 100 000$ gross margin, then your business can be valued between 600 000 and 1 000 000$.
These are classic basic values for digital startups.
Now given how sulfurous is our industry, there's a lot less buyers... and that diminishes the value.
So expecting +/- 3 X your yearly gross margin is reasonnable. But again, that depends on all the potential values mentionned above.
Last parameter: how urgent is it for you to sell? Like in all deals, if you're in a hurry for cash and buyers smell it, you won't get the best deal
.
Of course everything stated above is just from my little experience and knowledge, I don't pretend it's pure truth, just trying to help