Upload & Sell: Off
I've both the 40D and 50D, it sounds odd but the 50D is mostly my backup, along with a G12. IQ is why I use my 40D as primary...but that discussion is best for another post/day; I do love the 50D's LCD.
If you are considering the 7D, test it's new AF before you buy. The 5D2, 6D, 60D all use the same basic focus point system that has the red rectangle confirm option. The 7D uses a more advanced black rectangle based system like the 5D3 and 1DX. The 7D gets great reviews and lots of FMers use it quite successfully.
One question...are you a hobbyist or a paid pro? If you're a second shooter sometimes, what does your primary shooter use and more importantly, what body; crop or FF, would compliment what your shooting assignments require.
You've some nice fast glass, the 50D gets you pretty good FPS and reach, I'd think if you are looking for better IQ you might consider a FF body. Take a look at the 1/2 dozen 6D threads here on FM, most include a ton of info on the 5D2, 5D3, even the original 5Dc.
The 5D2 is a killer camera and it's price point right now is incredible...meets your 1500 spot on. There are scores of hobbyists and pros here on FM that exploit the 5D2 for all it's worth and their images demonstrate it's amazing/ground breaking abilities.
Good luck deciding