Based on my friends exprience with the GPT site that he has built, he spent lot of money in beginning for promotion purpose,yeah you know what i mean no one knows or care about your site, unless you tell them in this case is promote it and it needs more budget, however the hardest part was treat your members right and build loyalty , anyway the gpt site is better than ptc, people are too bored clicked ads, watching videos or playing games is a good way to earn money in GPT site, as for me, i might be limited to a strict budget when i want to start this business.
You can start a GPT website with around $100, depending on your needs. Then you should have another $100 for the members first payments, but what makes you get the green is getting the right ads and doing the right math.
If you place a ad at $1 (example) and the user earns $2 per click on that ad, you will always lose $1.
If I ever sold this services I could guide you while you do this so you know what you will be doing.
You forgot about the advertisement, if you don't invest in it you will get nothing out of the website because as a faucet or gambling website it needs stable traffic to reach an actual income