What's the price of sentimental value? An artist and a mathematician's formula for the cost of love

Exactly how much have your romantic relationships cost you in time, money and effort? Does an object's monetary worth increase because of the emotional price the seller endured for it? Can you turn sentimental value into cash?

That's the line of questioning theatre artist Haley McGee was trying to answer when she enlisted the help of mathematician Melanie Frances to develop a formula for the cost of love. The result of their collaborative effort is McGee's solo show, The Ex-Boyfriend Yard Sale, which premiered in London at Camden People's Theatre in November 2018. The following February, the show had a sold-out run in Toronto at the Theatre Centre's Progress Festival.

The show was inspired in part by the credit card debt McGee had to pay off after she moved to the U.K. from Canada. "I looked around my flat and realized the only things I could actually sell — the only things I own that have monetary value — had all been given to me by my different ex-boyfriends," she said. Her quest to accurately price the objects was what led to the idea of coming up with an algorithm to measure sentimental value.

Part autobiography and part commentary, The Ex-Boyfriend Yard Sale explores McGee's personal stories, tries to answer questions about emotions and economics, and maps out how love and money intersect in our lives.

In this video, you'll see McGee rehearsing for a third run of the show at Toronto's Soulpepper Theatre (which was ultimately cancelled due to COVID-19) along with snapshots of the items for sale and snippets of the formula — like the "relationship index," which measures the quality of her relationship with her exes on a scale of one to 10, including how hard they made her laugh, the ratio of fun to misery and how good the sex was.

McGee's memoir based on the show is set to be published in May 2021 in the U.K. and February 2022 in Canada. She's also launched a podcast called The Cost of Love with Haley McGee, in which she chats with a wide range of experts — from an AI specialist to a romance author, an egg-freezing aficionado to a couple's therapist, and a reality TV producer to a sex toy retailer — to learn what they can teach us about love and money, relationships and numbers.