I have also seen these chips on ebay and wondered if they were real or not.
I talked to TI and sent a copy of the posted pic to them to see what they had to say.
Here is a copy of their reply:
Hello David,
Thank you for contacting the Americas Product Information Center at TI.
I have researched the two parts that your provided, and it appears that that the part that has the below topside marking of
BB
OPA627AP
21ZS44W
matches our mart marking symbol for what the topside marking should appear as on the top of the OPA627AP chip. The second chip that has the part marking of
BB
OPA6727AP
0044WM8946
Does not. If you did not purchase either part from an authorized TI vendor such as Digikey, Avnet, Arrow, Newark In One, or Insight, we have no way of guaranteeing either part. But the first part does appear to have the correct nomenclature for the topside marking.
If you suspect that the parts that you have are not valid, and you did not purchase from a TI vendor, please contact the vendor from which you purchased the parts from.
I hope this information is helpful and if you have any further questions please feel free to call or reply to this email.
Thank You,
Dennis Williams
Texas Instruments
Semiconductor Technical Support
http://www-k.ext.ti.com/sc/technical_support/pic/americas.htm
I would stay away from ebay venders of expensive opamps.