Welcome to the boards and grats on getting a long arm. Lucky duck. I would need a bigger house. Always thought the family room/converted garage would be my long arm space, but I got a husband instead and overall (most days) I think that's a better deal.
There are some used machine dealers, here is a page of nationally selling machines through my local resource of Quilters University
https://longarmuniversity.com/MachinesForSale.html
I've never dealt with them but there is also Whitlocks
https://whitlocks.com/