The one issue I always have with ebay and Tri-X is that I see people want to have more money for their expired Tri-X then I pay for my fresh Agfa APX/Rollei Retro. Of course the film was more expensive in the first place but still, it comes of as a little strange ...
But generally EBay is quite a nice place for film, and if it doesn't have to be Tri-X I would recommand having a look at AGFA since their b/w-stuff is quite good. Unlike their colourfilm, that was rather ... well I don't want to speak ill of the dead. Bad, ok thats what I thought it was. However I don't really know how things are in the US, here in Germany/Europe there are companys with the rights to AGFAs films (agfaphoto is one brand, but the films branded Rollei Retro are really close too) so they are widely available and come at about 2,80€ a roll even for single rolls.
The current Agfa Precisa CT100 is fine...it's "Made in Japan", so obviously a Fuji emulsion. I've also used some of the current Agfa B&W, which I also find good. There has been speculation that this is from "old " frozen master rolls coated before Agfa went out of business around 2005, but, whatever it is, it seems OK to me. :)
I found the Agfa Vista 100 and 200 were quite good when printed by a decent technician. 400 and especially the 800 I was not so keen on.
About 4-5 years ago was the best time for film on eBay. I regularly found bulk tins for $15-20 and 120 films for $1 or less as pros emptied their freezers as they went digital (one of my best scores was 90 rolls of 120 Plus-X for $85). I am blown away by the prices these days. There's an old expired roll of Fortepan or Fomapan from the 60's that someone wants $10 for! PLUS shipping!!
Interestingly the company that has the right to sell stuff under the label "AGFAPHOTO" (lupus imaging) is actually in walking distance from me. Their film is labeled as "Made in Germany" but as of now I could not find a date of production on their films or the packaging. It's al little strange since Gaevert, the company that was part of Agfa and now produces the films sold under the Rollei brand, is in Belgium and I wasn't aware there still was a company in Germany producing Afga films. But then again, as long as the film is good - and it is - I don't care that much where it was made ;)