My guess is that it will still resemble a power law curve.
If we just examine YC exits to date, Heroku and OMGPOP are around $200M each, $400M in total, which is likely over 50% of the rest. If we remove those too, there are a few exits in $30-60M range (Loopt, CloudKick etc.) which are quite likely to be over 50% of the rest. At the lower end of exit price curve, the power law might not hold, as acqui-hires typically have a rather standard price ($1-2M per an engineer)
If we just examine YC exits to date, Heroku and OMGPOP are around $200M each, $400M in total, which is likely over 50% of the rest. If we remove those too, there are a few exits in $30-60M range (Loopt, CloudKick etc.) which are quite likely to be over 50% of the rest. At the lower end of exit price curve, the power law might not hold, as acqui-hires typically have a rather standard price ($1-2M per an engineer)