I haven't owned either one, so this is just my speculation. With the cash thrown in as you describe, the swap seems to be about right value wise (assuming your Optimas are base models and in good shape). I suspect the Optima will hold its value just a tad better than the Timber Ridge. I guess it pretty much depends on which you prefer, break open or striker. Accuracy potential is probably about equal. I assume your Optimas have been shot and your friend pretty much knows exactly what he would be getting accuracy wise. The NIB TR may be a tack driver - or may not be.

Why not just do a deal on one and see how you like it.