Fair. That's a clever solution to getting around the problem of needing to duplicate your set up.

It is a big step up in complexity though, as you now need an IR receiver as well as an IR blaster, some sort of physical button(s) on the device that puts it into "learning" mode to detect what signal it needs to duplicate (and indicate if it's learning volume up or down), and all the additional development overhead each of those entails.

You'd probably see a good jump in the parts cost too. Especially as, when adding more controls and sensors, it increases the complexity of the enclosure you'd put all this in, meaning you probably would need some CAD work done as well. Or someone willing to do some precision woodworking.

All told it's probably about three to five times harder than just knowing the correct IR sequences up front and baking them into the product, so you'd see a commensurate increase in price.