Thanks so much man you're awesome!

Repaired my old (2nd) N9 today with a screen bought from universalaccessories1988 on ebay for 49$. The screen looks and works great, proximity sensors work. I haven't used the phone extensively though and will update this post if something goes wrong.

Followed instructions at http://www.youtube.com/watch?v=9dxsTGpGRhs
Nokia N9 Screen Replacement - LCD (AMOLED) + Touch Screen (Digitizer) + Proximity Sensor by LE55ONS on youtube.

It took about 20 minutes to do it, and I'd say it can be done by anyone who has the screwdriver (T-5) and can follow instructions. The replacement screen does come with the screwdriver, but in my experience the provided screwdriver isn't well made (you're better off buying a good 32-head screwdriver kit in the long run).

I ordered from the same place after reading the above.
Screen arrived in 12 days, I just put it in and it looks good.

Note that the proximity sensor is not included, so you transfer it from the old assembly along with the light guide, but it is quite easy.

I wonder if I can sell my old cracked but usable screen?