Ebay sellers switching tubes

so what out for ebay sellers , havinga  NOS tube with good/OK/excellent print in the item pic,,and  then swaping out for another tube with less print or no print.

w/o print the tube is not worth very much, unless it is NOS, not strong, but true NOS. 
If you buy a  NOS/low quality print, i would finda  tech who can test it against the vlaues stated by seller. 
I have so many RCA's and other 12AX7's arriving daily,,,i failed to see seller's listing vs tube acutally sent,,also make sure seller puts INVOICE inside package (allows you to ck your purchases more accurately)
Thus
If you buy off ebay, senda  note, I want the tube in the pic sent, not another and please send with invoice and if showing test scores, ask to have text scores taped to the tube,,,, this insures more honesty among sellers.

Please add any notes you have from your experiences. 

NOS with strong print , prices will sky rocket,,,,with boxes add another 20%, 
If I buy NOS, with low print/no print,,i will let seller know,, i will ship out to be tested,,if not close to your scores, i will ask part refund or ship back to you. ,,and say <<fair deal?>>
It is good we all get these things out in the open, to help newbies comming into the tube world from having to experience all the rip off/bad deals we;'ve all gone through. 
Sellers will have to come clean or go out of busniess with negative feedback.
Wish i had been more careful cking packages vs the acutal listing pics. 
Now i have  to send a  bunch of mystery AX's off to be tested./labeled,,,not sure if they are CBS/GE's or RCA's. ,,and how they test.