$3000 treadmills are commercial-grade treadmills. This type of treadmill has a heavy-duty frame. Some can weigh over 350lb. Treadmills in this price range are usually seen in your local gym and, if bought for home use, are bought mainly by serious runners in training for marathons, etc. Most people do not need a treadmill costing $3000, especially if you only need a treadmill for light to medium cardio.