As with most things, you tend to get what you pay for: except with wine, golf clubs, or anything with the Blichman label on it.
I say this a little tongue in cheek though. As with anything, there are levels of quality. If you are a professional race driver, an off the lot performance car at any price isn't going to cut it. For a weekend warrior though, it will, and for a fraction of the price the pro is paying (though he is likely not paying for the stuff to begin with).
Point is, for a homebrewer, the effort of cleaning the seals isn't usually a big issue between each batch, so even the blichmann is fine.
The BH fermenters are pricey, especially the jacketed versions. I'm sure you will love it though, as it is hard to fault from the sounds of things.
I think the gist of the thread though is how can get the (least expensive) best conical (and what are the tradeoffs).
I am curious about the post Kirbuno made showing a failure on a seal under pressurized fermentation. Can I ask why do you ferment at 7psi, how you supply the pressure, and what is the benefit? I understand that there is hydrostatic pressure in all fermenting vessels due to volume of fluid and height of the vessel. Most commonly (I assume) closed fermentation with an airlock/blow-off is performed with no significant head pressure above the wort/beer.
TD