I bought from
http://www.ebay.co.uk/itm/400251899917 in August 2015, was £32.10 at the time. I'm in the UK.
I received an LG LP125WH2(SL)(B3) which on close inspection had one dead pixel (no light). It's only noticeable on a light background, and even then I need to pay attention to find it (1 pixel is small in a whole screen) so I decided I could definitely accept that rather than faffing with a return and another round of screen swapping. Otherwise the screen is great: high brightness (I use it at 25% brightness in office), good viewing angles. I've had no ghosting or other issues. Mine's in an X220 but the X220 and X230 screens are the same fitting. Installing the screen was fine, just pay attention to the magnets at the corners not moving.
I also spent a fair amount of time wondering "what if", might all these screens have multiple dead pixels/other issues, considering the potential risk of ghosting/white spot issues appearing later. Though I concluded that while there may have been a ghosting issue with an early batch of screens in 2010 or 2011, a screen sold years later now won't be that batch, and the internet is full of people who bash & abuse things and then wonder why they get damaged, and/or if a company sells a million laptops there will always be a small number of issues over something (referring to the white spots on screen issue).
Given that the screens are just over £30 I assumed the sellers wouldn't be interested in me contacting them for them to guarantee a particular panel model & revision with zero dead pixels. The sellers also probably don't know much about any particular screen, just buy in bulk and sell on. So I just went ahead and bought. All the reasonable sellers should have a 14 day returns policy, so if you what you receive isn't OK for you, you can pack it up carefully and return it at your cost and try again. As you say, the guaranteed route is so much more expensive it's not worth it.
The IPS is so much better than the TN it is worth doing it.