I'd do it just because of the trade values.
I disagree.
If the OP really wants to try to get profit from the trade, it'll take up more work, time, and effort than you would expect to gain ~$150 or whatever.
Though you would have more of a range with the 24-105, I personally would keep your current lens because they are faster and the 17-50 is a good lens.
Unless you prefer the IS over the wider aperture, and maybe more flexible range, then go with the trade
And please don't get the 24-105 just because it's an "L" lens. It's the most ridiculous excuse I hear everywhere.



