Peanuts by Charles Schulz for January 16, 1973
Transcript:
Snoopy lies on the doghouse and thinks, "I spoiled Woodstock's party!"<BR><BR> Snoopy sits up and thinks, "He had invited this cute little bird that he's in love with, but he never got to talk with her because I talked with her the whole evening!"<BR><BR> Woodstock flies upside down toward Snoopy. Snoopy thinks, "So he sent me a bill for six dollars for a broken heart! Oh, Woodstock, my little friend of friends . . ."<BR><BR> Snoopy hugs Woodstock and thinks, "Don't you realize that your heart is worth more than six dollars?!!!" Woodstock sighs.<BR><BR>
So assuming that Woodstock is a yellow canary (first search result on Google) then he would probably be around $100 – $200 which is, as Snoopy says, much more than $6. Of course, however, that also includes the bones, feathers, blood, and organs of the bird so it would be overpriced if you only want the heart of the bird.