Looking at "Recent Games" in Steamspy Mass Effect Legendary Edition leads the pack with 500k to 1 million sales. Solasta is on the first page though, at 200k to 500k sales. Given the rather stark differences in marketing power behind those two publishers the Solasta result actually looks pretty good!
Only time will tell whether we get a sequel, but 500k sales (give or take) is probably a windfall for a small studio like Tactical Adventures. My confidence in their next project getting traction is very high.
I mean, I am hopeful as well. One thing to keep in mind about ME Legendary edition is that most sales probably went through Origin - EA's games platform - and not through Steam at all. Since the game has to be run through Origin anyway.
500k is not terrible. Its about 20 Million Gross - minus 30% for Steam is about 10-14 million for Tactical Adventures adjusting for sales - on a budget of 250k.