There are about 40 in my collection, and still growing. one functioning treadle from the late 1800's, three more in cleaning and rebelting stages. About 15 vintage machines in cabinets - 1 needs to be rewired, another needs a shuttle, About 15 portables, many of which are also vintage, or vintage clones. Two embroidery machines, a serger, and a long arm.
There are 6 which I personally use on a regular basis. The rest are used for 4-H students. They use the cabinet machines at the house, I take the portables to outlying ares for classes. Occasionally, I loan them out. Because I use them for 4-H, many of the machines are donated. I watch for the inexpensive, clean and repair them myself. The cost will come when I'm forced to build a new studio to house them all. (grin)