Who bought the Field of Blood, Judas or the Priests? This is similar to another question &quot;How did Judas Die&quot;, but is specifically addressing another aspect of the story.
In Matthew we have the priests purchasing the field:

Matthew 27:5-7 (NASB)
5 And he threw the pieces of silver into the temple sanctuary and departed; and he went away and hanged himself. 6 The chief priests took the pieces of silver and said, “It is not lawful to put them into the temple treasury, since it is the price of blood.” 7 And they conferred together and with the money bought the Potter’s Field as a burial place for strangers.

And in Acts we have Judas purchasing it:

Acts 1:16-18 (NASB)
16 “Brethren, the Scripture had to be fulfilled, which the Holy Spirit foretold by the mouth of David concerning Judas, who became a guide to those who arrested Jesus. 17 For he was counted among us and received his share in this ministry.” 18 (Now this man acquired a field with the price of his wickedness, and falling headlong, he burst open in the middle and all his intestines gushed out.

This seems a clear contradiction in the New Testament. What is going on here?
They both did - it just depends on perspective for application of the word "bought".

It was Judas' money, and it was the priests who used the money he returned to them to buy the field.  They bought the field because they could not accept blood money and return it to the temple treasury.

In essence, the priests bought the field on behalf of Judas.  

This is just like when my mother would give me money to go to the store to buy some groceries; we both bought the groceries - I did the physical act and she did through providing the financial resource (and, back in the day of single income families, so did my Dad in earning the income to begin with).