Ok so according to vo-wiki I need 8 trading and 4 mining to buy a behemoth from a non corvus place. I currently have 9/9/10/8/4 for my license levels and cannot buy a moth. I have checked a TPG and a valent and niether offer behemoths for sale.

Anyone know why?

That's very odd. One possibility is that they may have changed the license requirements for the Behemoth, but I haven't seen any sign of that. Another possibility is you may not meet the standing requirement for the Behemoth, but in my experience I've been able to buy Moth's everywhere I was able to dock, even with negative standing, so I don't think that's likely (again, unless it's been changed).

I agree it is odd, because on my first char when I had 8/4, I was able to buy moths everywhere I could dock. I was wondering if something changed really.

I haven't changed any requirements. Unless I screwed something up. But.. no, I just edited the file the modifies the properties, not the requirements.

Note that all stations don't carry the thing (not a single station in Azek does, for example, and half of them are TPG). In fact, it's UIT stations, not TPG, who carry the Behemoth. Try Dau!

The Behemoth is a "generic" ship, sold by all factions in the game. It is still possible that the stations mainbutter was at didn't sell it, but it's not only UIT stations that sell it, I know for a fact that at least some TPG stations do sell it (and IIRC, it was TPG that originally designed the Behemoth).

In general, it's "Capitol" stations that sell the Behemoth. You may find a "Commercial" station or two that does, however.