It's long out of warranty, so no free repair. I've heard quotes around $1K or so. Your instrument panel has the same problem and will likely bubble at some time as well (another $1K or so). If you do the MCU2 upgrade, you get a new instrument cluster and a new main screen and electronics. It may seem expensive, but it's really quite the bargain as it includes installation labor. Compare that with a Lexus 9" screen/module parts cost about $4000 + labor and offers no CPU or memory improvements. No matter which option you choose, the new LCD displays are designed differently and do not have the layer that causes the bubble problem.
Note that the MCU2 upgrade kills your radio, and there is an option ($500?) to switch from the old incompatible analog radio to a digital FM/XM radio. That can be done anytime, so it's not necessary to spend the money now if you don't need the radio. Streaming will still work.