Unlucky Baseball Card

Riddle: A young man decides to buy a collector's baseball card. He pays $60 for it. After a month, the value of the card has increased to $70 and he decides to sell it. But already a few days later he regrets his decision to sell the collector's item, and he buys it again. Unfortunately he has to pay $80 to get it back, so he loses $10. After a year of owning the baseball card, he finally decides to sell it for $100. What is his overall profit?

Answer: $30.00. Overall profit, not net profit!

Source: https://www.riddles.com/502

A young man decides to buy a collector's baseball card. He pays $60 for it. After a month, the value of the card has increased to $70 and he decides to sell it. But already a few days later he regrets his decision to sell the collector's item, and he buys it again. Unfortunately he has to pay $80 to get it back, so he loses $10. After a year of owning the baseball card, he finally decides to sell it for $100. What is his overall profit? — Unlucky Baseball Card by Anonymous v1.

Riddle: A young man decides to buy a collector's baseball card. He pays $60 for it. After a month, the value of the card has increased to $70 and he decides to sell it. But already a few days later he regrets his decision to sell the collector's item, and he buys it again. Unfortunately he has to pay $80 to get it back, so he loses $10. After a year of owning the baseball card, he finally decides to sell it for $100. What is his overall profit? Answer: $30.00. Overall profit, not net profit! — by Anonymous v2.