just my opinion, but seems like you get what you pay for when it comes to rod ends... $8.50 each sounds like you'll be replacing all of them every year, or they could pretzel more expensive bits if they fail...
again, just my thoughts... take them for the $.02 they're worth.
you could also consider alternate tubing size... if you get tubing with enough wall to machine them directly (without the adapter) it could be worth the tubing cost to avoid the adapter cost???