The painting of a face, created in a graffiti style, was layered with references to money and had a pound sign in the eye.
The idea came to Ms Roskell after reading that Monopoly was releasing a cashless version of the game.
She told BBC Radio Northampton’s Annabel Amos: “My mind went to the money they no longer need. You see these barmy things like someone selling a banana for millions – so why not do a fun play on that? It’s almost like fake it till you make it.”
The artist began painting again after years as a graphic designer.
She had stopped until a creative challenge with a friend helped her rediscover her style, moving away from traditional landscapes to more expressive, abstract work.
“I love it now – I’ve sold pieces to America, Finland, and lots through social media,” she added.
Since bidding opened on 1 July, Ms Roskell said she had already received several colourful bids in Monopoly money.
