That’s a no no. Don’t help anyone for free. They want a sample? They need to buy one. You’re losing your time “helping” them, time you could be using for anything more productive. This is the internet, we have to suspect from any person who approaches us. Specially if they want work done for free. Most are scammers or people who won’t give you the money you deserve for your time and work. Don’t waste your time that way. Giving the extra mile means providing an excellent service, not offering unpaid/extra work for free. Fiverr is a platform that favors buyers instead of sellers, so they may abuse the system and yourself as a seller if you let them to. Set your boundaries and don’t let any buyer, no matter how appealing their offer may be, cross them. Thanks a lot for your valuable advice.