I have no experience with the sprag clutches, but I do have a lot of experience with Ebay.
Sellers on Ebay come in varieties from excellent to awful. The worst will create ads that are intentionally misleading. Others will accept your money and not ship anything. There is a flaw in the Ebay system that removes a buyer's ability to leave feedback after 60 days, and will also remove the purchase listing from a buyers "front page". Unscrupulous sellers are taking advantage of this flaw by promising LONG delivery times. The buyer can't complain until the promised delivery period is over. If this is more than 60 days, the buyer has lost the ability to leave negative feedback for the seller. After such a long time, with no reminder on their "front page", buyers tend to forget about these purchases. The bogus seller gets to keep some percentage of the transactions and simply refunds money to the buyers who complain without incurring any penalty.
My point is that it isn't JUST quality issues that one is contending with. There are also very long waits for delivery, in most cases a total absence of shipping tracking information between listing the shipment number and the delivery, and a possibility that the seller has NO INTENTION of ever shipping anything. Sellers from China are the worst offenders, in my opinion. If I need a crucial part, fast, I will purchase from a domestic or UK source.
That said, I do buy from Indian and Chinese sellers via Ebay, But I'm very careful to monitor the progress of any purchases. Ebay has the buyer's back, I have always gotten my money back. But, it did take me FOUR attempts to purchase oil filters before any were actually delivered.