You'd be wrong. The 'espresso' window is 6-9 bar of pressure. It's not very hard to build that much pressure, really. I have a pump based manual hand espresso brewer (the Picopresso) and it hits that pressure just fine from an even simpler mechanism.

The Flair can definitely hit espresso pressure; I get excellent crema from it. As I said above, the biggest limit is high-altitude temperature regulation. Water boils at espresso temperature at ~ 2000' elevation, so if you're above that you cannot control the water temperature. With a pressurized machine, you can go as hot as you want.

What about the OXO press thing ?