Ask HN: Selling a conference – how do you value it?

I've been organising a technical conference for 2 years now in France. Both years it went well: around 200 attendees in 2013 and 250 in 2014 and made a profit both years.

Now a company that organises already many technical events approached me to see if I'm interested in selling them mine. I am but I don't find anything online about valuing a conference.

Sure, I can do as I would for any other business but it's not any other business and I was hoping to find at least some average multiplier or similar to kick off the conversation.

Any hints? Thanks!