Who's paid for curiosity ahead of Romeo's exchange with Tybalt, finally (8)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

MET (paid for) + CURIO (curiosity), with R (Romeo) switching places (exchange) with the last (finally) of tybalT. Of course, Mercutio is the ‘who’ that is killed by Tybalt when stepping up for Romeo. Before Romeo kills Tybalt. Before everyone dies. My favourite clue of the year.