Town Halls, VFW, stuff like that, is really cheap. That's where we have ours, like Mabel was pointing out.
These are going to be much less expensive than commercial venues (hotel meeting rooms or restaurant banquet rooms). The "disadvantage" is that especially with private organizations like the VFW, Grange, etc. they often don't have a paid staff person or an office phone to call, so the Mass organizer needs to track down their volunteer who handles hall rentals. And, the room will need to be set up, taken down, swept, etc. by the group renting it as there is no paid staff for that, but that is what makes them less expensive. These groups are usually looking for hall rentals to help them afford to keep the place. Also, if a chapel member is also a member of a group that has a hall (Am. Legion, VFW, Grange) they might get a reduced rate.
Many towns have community centers, senior citizen centers, library meeting rooms that are available at low or no cost to citizens. They are not always available on Sundays though, or an extra fee is charged to have someone open and close the room on Sunday.
Here in WA I know of churches that hold services in public school cafeterias or auditoriums. It is up to the discretion of local school boards to do this, but as long as enough is charged to cover all expenses, and the opportunity is available to any religious group that asks, it doesn't seem to be a church / state separation issue. When my family moved from Seattle to a farm, from 1955 until a church was built in 1964 we went to Mass every Sunday in a public school cafeteria. Different families took turns setting up and taking down. We were allowed to store a folding confessional screen there but Father brought everything else each Sunday.
Another option is a local funeral home chapel, which typically seat between 100 - 200. They often have pews (though now many are replacing the pews with chairs to make the space more flexible). If the funeral home serves many Catholic (evening Rosary service), Orthodox or Anglican families they may even have pews with kneelers. They will also usually have an electric organ. I noticed in the local paper this morning that a new start up evangelical church was meeting in a funeral home chapel.
I don't have cost information to share, I apologize, but as others have also suggested, there are many options besides hotel meetings, and they will often be less expensive.