That's a repair I've performed many times. Of course, I replace the Light Tunnel, not reglue it. I usually charge $112.50 for the labor, plus any shipping for the parts and return of the projector. I ship UPS and insure it. The projector is cleaned and the firmware is checked for the latest version.
There is one other common problem with these projectors and that is the Color Wheel. After a while, the bearings start to fail. If this occurs, you will hear a whine or "buzzsaw" noise when it powers up. If you hear this now, then you can count on it failing soon. The cost on that part is $175. Now....replacing the Light Tunnel is one thing, but if you're looking at replacing both components, then you might want to reconsider as the cost gets up to the point where you have to question whether you want to that money into this projector or towards a replacement.
I am out of parts right now, I'll have to order more. If you're interested, pm me.