Just remembered one problem awhile back with a tablet purchased off ‘zon that didn’t work properly. Difficulty was an electronic problem that wasn’t readily spotted by the seller. They even debated my claim but Pay Pal buyer protection policies resulted in a full refund plus shipping. I feel that, plus my credit card refund protection, makes most online purchases fairly safe.
You also have seller feedback to consider. I sell occasionally on the ‘bay and I am honest and forthright with my item description and entire transaction. My selling and buying feedback standard is 100 percent, and I think most ebayers are this way, or their business, and usually significant income would eventually collapse.
In summation, online transactions have to be weighed in favor of the purchaser - by the selling organization - to even make online shopping work effectively. You are buying something sight unseen - with only photos and description as your guide. So conduct that due diligence and you should come out fine. Time to move on after this lengthy screed. Good luck in your hunting and gathering.