Burned Out

I recently got caught up in the tube swapping craze. I have a tubed amp and preamp. I researched things as well as I could for only having access to the internet and forums like this. I also was in contact with the owner of a very well known vintage tube dealer. I bought two tubes from eBay from dealers with a long history on eBay and high customer review rating. Both tubes from eBay were for my preamp, one  was a Brimar and the other Melz 1578 6sn7 tubes manufactured in the 50’s or 60’s. The Brimar only played through one channel and at first dealer tried dispute the fact that it malfunctioned and then contacted me saying he was now having the same issue. The Melz red plated on me and was very microphonic. The dealer is in the Ukraine so I’m waiting to see if I will get my refund. And, last but not least one of the most reputable dealers recommended a tube RCA and has stated he stands behind his product. But, what happens when his product causes damage to your preamp? My preamp now plays only through one channel. When I called up the dealer about the noise the tube was making, I was told follow the instructions regarding microphonics and that there was no way the tube would damage my equipment. There was a recommended break in period of around 48 hrs. Well long story short, my preamp is not functioning and has to be sent back to manufacturer and as of on out $115 for the tube. So my question is are NOS tubes worth all the risk? Are the newer tubes that bad that I have to sacrifice the working condition of my gear for a possible sound improvement? I would like to know your thoughts. Are tubes the Shuguang Black treasure, Northern Electric, a safer risk. I’m venting right now, but looking for answers