I have an American Harvester I got at W-m many years ago. It's still going strong. Just be sure the one you pick has a fan and a thermostate. Some foods are better dried at a lower temp and some a higher (jerky).
If you are only planning on doing mushrooms and the occasional veggie or jerky, I think this brand would work for you. Be sure and buy a few extra trays and the roll-up liners. Like another comment here, I use those liners when I do herbs or small bits that would sift through the tray openings.
Some say a very light coating of cooking spray will help with the sticking. I just soak my trays in warm soapy water to clean them, using a medium brush on the tough spots.
I dry mushrooms, (powder some in a small food processor to add to any beef or pork roast & gravy. Makes it extra special but not "mushroomy"), onions, peppers, tomatoes, greens, cooked veggies like corn or carrots, apples, pears (family loves pears), strawberries (ground up to add to yogurt- YUM), ground meat jerky (occasionally). Shredded zucchini is great to dry. It dries down alot and you can store 2-3 base-ball bat-sized squash in a quart canning jar. Reconstitute and make into bread or add to soups.
“The greatest thing I have learned is how good it is to come home again,” -Eleanor Roosevelt