Lemnis Gate

how much for? from who or which site? you really didn't give much context

You be 4 years on sg and have level 7, you should know such basic stuff because only you have the informations that would be needed to answer your question.

Source, price etc.

I don´t quite understand your questions, free in what way ??
From what I can see on Steam this is a ~ $ 20.- game, about to release ..
I wouldn´t expect it to be in cheap bundles soon, so especially if you were to make GAs of it around it´s release date, you should receive full value on SG for them.
I can´t know for sure, but imo should you decide to do so you will have heaps of participants!

With any PVP only there will always be a (high) chance the multiplayer becomes dead and then a dev tries any possible way to still dump some copies, or even before it gets released to get some people in,

Unless you mean you know a russian site or something where it's 95% off and you mean that.