If price is the main concern, there are safer ways to get a deal than looking for "extra quality" keys:

Guitar Pro is the industry standard for a reason. Investing in a legitimate license provides:

Keep an eye out for seasonal sales (like Black Friday), where the software is often discounted by 20% to 50%.

If you own an older version of Guitar Pro, you can upgrade to the latest version for a fraction of the full retail price [4].