Barry Downs, 64, was caught by Trading Standards selling the brooches for £2.99 each on Stanley Market, County Durham, in the run-up to Remembrance Day 2017.
He was found to have 287 poppy brooches on his stall and a further 182 in his car parked beside it.
Some were Scottish poppies with four leaves, while others had two leaves, Newton Aycliffe Magistrates’ Court was told.
Downs, of Coltspool, Kibblesworth, Gateshead, admitted seven offences under the Trademark Act.
Said to be of good character, with no previous convictions and 30 years’ experience on the markets, Downs was ordered to carry out 80 hours of unpaid work, handed investigation and prosecution costs of £950 and a victim’s surcharge of £85.
After the case, Peter Milne, Community Fundraiser for the Royal British Legion in County Durham, urged people to buy official poppy products.
He said: “Money which is given to unscrupulous traders simply deprives the Legion of the opportunity to provide help and support to the Armed Forces community across a wide range of areas from benefit, money and debt advice to war pensions and care homes.”
As he left court with his face partly hidden by his hood, Downs said: “I apologise profusely, it happened unintentionally.
“If I had realised I would not have got involved with it.”
Sarah Griggor, for Durham County Council, showed magistrates examples of the brooches that he was selling.
She said trading standards Officers visited Stanley Market on November 2 last year after they received complaints.
They found a table laid out with brooches, many of which were poppy-shaped, Ms Griggor said.
Downs told the officers he was not associated with the Royal British Legion and following that, the items were seized.
In February he was interviewed under caution and he confirmed he was selling the poppies for profit and believed it was legal to sell them as they were widely available on the internet.
He said he bought some of them from a wholesaler in Manchester while he had swapped others with an unknown man on the morning of the seizure.
Bill Davison, defending, told magistrates: “You are dealing with a man of good character who has been carrying on in business in Front Street, Stanley, for many years.”
He said Downs did not make enough inquiries about the copyright on some of the items he was selling, but he was not involved in any kind of “national scam”.
Mr Davison said Downs had receipts showing he bought brooches for £150 and was looking at making a profit of around £240 - a figure disputed by the magistrates.
None of the poppies had the Royal British Legion markings on them, Mr Davison said, adding: “It is the shape of the poppies which is the breach of copyright.
“Yes it is an infringement, yes it is unfortunate that it is poppies in particular, which is a worthwhile charitable cause, but this is a man who has not gone out of his way to commit these offences.”