how much money do you invest in ptc pages from your wallet?

I guess it would depend on what you're doing with the investment, and how credible the site is. I sure wouldn't spend a dime without checking with others that have been successful on that site first. Personally, I don't spend any money at all. The only exception was for ClixSense, and that was after finding out that upgrading would definitely be beneficial. I paid $10 to upgrade and recouped my investment within ten days, so the rest of the year's earnings is pure profit.

If you're talking about buying referrals or upgrading, I wouldn't recommend using any money other than what you've earned online. That way, if it doesn't work out you're not actually out of pocket.

This is my questions too if it will of advantage to buy referrals or upgrade. Upgrading needs a lot of investment. Perhaps buying referrals will help but we have to be sure it is a legitimate site. Have not tried buying ref but it will take time to reach payout without referrals.