PURCHASE AND SALE AGREEMENT by and among PMF FUND, L.P. PMF TEI FUND, L.P. PMF TEI (OFFSHORE) FUND, LTD., PMF INTERNATIONAL FUND, LTD., ENDOWMENT ADVISERS, L.P., THE ENDOWMENT MASTER FUND, L.P., THE ENDOWMENT PMF MASTER FUND, L.P., and HARBOURVEST –...