If it had binding and blocks, and was a recent model, I'd still have to say Japanese. Likely still a killer bass, but overpriced IMO. If they let you get close enough to note the serial number, if it is Japanese, it will say so at the back of the neck where it joins the body. If it is American, there will be a serial number on the back of the headstock. If Mexican, the serial number will be on the front, but I'm not aware of any American or Mexican P basses that have binding and blocks. The Japanese Fenders have a lot of variety though, so who knows what you might find in a MIJ model.
Regardless - that dealer sucks. Buy one off the internet, and then take it in to that dealer for service, and make the local dealer your bee-yatch. Tell them "I wish I could have bought yours, but I when I was on tour in the US and needed a bass, I ended up paying *way* too much for this one at a dealer in NYC, and besides, you wouldn't let me play yours last time I was in. No hard feelings, though. What do you have for strings?"