You did wonderfully well, Martin. The fact that client found and chose you to write that poem shows it was meant to be. £500 for 750 words is exceptional, but the time restraints etc. did put you under pressure, and the value of our work is really what someone is willing to pay, after all.

Writing personal poems for clients to give to their loved ones for birthdays, anniversaries, and even after break-ups is something I do often on Fiverr, but I have never made that sort of money. The length of time I have to write it determines how much I will charge, but my basic charge is by the word, not by the hour.

If you can get that kind of money for every poem you write you are on a winner. Keep that client, and hopefully he will recommend you to others.