Re: Best A/B switch for the buck on the market today ?
I think you could do that with a Boss LS-2 for about $60 or less almost brand new. (mine was $55 shipped mint!)
You'd just plug guitar 1 into the main input, then guitar 2 into loop A input. It shouldn't matter that loop A output(basically the "feed") is left empty.
With the LS-2 the loop A and B outputs are there to feed your separate effect chains, and loop A and B inputs are basically acting as returns.
No matter what mode you switch to, the pedal's true main output sends the signal to the amp. (or to any other effects you have post-pedal, in this case it's the entire pedalboard)
You then turn the selector knob to pick a switching format. You could actually have 3 guitars plugged in and ready. (A/B/bypass)
Never used it like this, but I don't see why it wouldn't work, and I believe the LS-2's loop-channel volumes are actually between the returns/"inputs" and the main "to amp" output jack, so they should be able to be used to balance any volume differences from one guitar to the other.
You could use loop A and B for the guitars instead of Main and A,,,,,,,just depends how you want to set the foot-switch function.
Also if using just the A and B returns you can select blend-mode to have them going at the same time with separate level adjusters.