No No. I haven’t received a 200$ tip. But my friend did. He completed an order for the Tee design and the buyer liked it so much that he left $200 as a tip and said he would be back next week with more orders.
Here is the proof: 
While I have received maximum $15 as a tip for a $5 order.
What is your story?
Thats Great !!
What I feel is your friend is charging way less then he should be.
How I know this ? Well one of my client told me while giving me a tip that I am charging way less then my competitors.I should Increase my price and then he tipped me because he felt that I was underpaid .
Some clients do change your perspective the way you look at things . 
I worked for my client 960 excel data entry with 5 dollar order,ask him i will be very happy if you left a great tip.
He send me 
and give me five star rating
