Since the only parameter you've given us is the price, and that it must be a handgun in 9mm or 45, I'll tell you what I would spend my $800 on and why.
High Power 9mm
Most popular handgun worldwide, parts available in Zaire or Argentina. It's been used by 63 different countries. It was the first "double stack high capacity" handgun, IIRC. It shoots better than most shooters and seems to fit most people's hands better than even the 1911. The 9mm is more commonly available worldwide too.
When comparing a 1911 to a High Power I find that the 1911 looks like a "workhorse" while the High Power looks like a "race horse". When you look at the inside of the gun you see an encapsulated recoil spring and guide rod. Also, there is no link pin to come loose, disassembly is a breeze and there's no blasted Barrel Bushing, which has been cause for frustration and inaccuracy since it's creation.
To me the High Power is the final evolution to all of John Browning's work. It's been said, "When John Browning created the 1911 he hit a Home Run. When he created the High Power he hit a Grand Slam."
OK, that's how I'd spend $800 if it were me. BTW, I just bought another High Power for that amount two weeks ago.
Don't get me wrong, I like the 1911, but I've come to love the High Power. It really is a superior weapon platform.
Biker