Many traders don't spend enough time researching the EAs market. Sadly, the EAs market is flooded with SCAMS - 90% of EAs are sold by marketers instead of traders and developers. Because marketers know how to attract your attention
with big words and promises, many people fall into this trap.
What should you do?
Look at the results, do not listen to words only. Backtests are good, but live results are the only thing that matters. Look for third party verified results - myfxbook.com is great for this purpose. Look for a long enough performance record - at least six months or more. Pay attention to the balance curve - if it is completely flat, STAY AWAY – it means that this is a "no-stop-loss" system, "martingale", or just another reckless system!
A healthy EA equity curve looks like a nice market trend - it goes up, but has some corrections/drawdown periods as well. Look at the number of trades - less than 100 trades is not representative enough. As a final step, look around in forums to check up on the reputation of a vendor and its products.