I need to know that I have a $5 gig for Subtitling videos. The buyer’s video is 21 minutes long.

My question is that what will be the total offer amount?

Is the $5 gig rate per hour basis ? or will the minutes be considered?

The buyer says that **"if you charge $5 for 15 minutes, then per minute is $0.33. so 21 minutes would be additional $2, as extra are six minutes, so 6 minutes x $0.33 = $2. so the total cost would be $5 +$2 = $7, right?"**

is the buyer right?

kindly guide me as I am new here on Fiver.