$200/night is a good price for a hotel room in Salem in May. The cheapest hotel in walking distance is probably the Hampton Inn. The Hotel Salem is literally right around the corner (like 150’ away) and is probably $250/night.
If you’re driving or renting a car, things get much cheaper within a 15-20 minute drive of downtown Salem. Danvers and Peabody both have things like Holiday Inns, Quality Inns, etc. Driving in and parking at the MBTA rail station is less than $8/day. The rail station is a 10 minute walk from Old Town Hall.
If you’re adventurous and not driving, there’s the Beverly (https://www.booking.com/hotel/us/the-beverly-beverly.html) which is the next town over and is a short walk to the commuter rail (the BurlExpo is a short walk from the commuter rail in Salem).
Last year, a couple of different groups booked large-ish AirBnBs within walking distance. As soon as you’re putting 3-4 people in a space, they get more reasonable.
There is a Facebook group (https://www.facebook.com/groups/BurlExpoInfo) which is set up for people looking for ride shares/room shares, etc.
Downtown Salem is very walkable and there are several hotels within easy walking distance of Old Town Hall, most shops, and all the places that we're going to be using for events. Old Town Hall is located in the center of a pedestrian mall. The closest you can drive to the building is about 250 feet and the closest garage is about 2-3 blocks away.
The Hotel Salem
209 Essex St, Salem, MA 01970
18 Washington Square W, Salem, MA 01970
11 Dodge St, Salem, MA 01970
The Salem Inn
7 Summer St, Salem, MA 01970
Salem Waterfront Suites
225 Derby St, Salem, MA 01970