I'm a firm believer in the old adage that "you get what you pay for." My recommendation is that if you are going to use this bike to lose weight and get in shape, then spend a little money. Visit the local bike shops and test ride some bikes. Pick one that you like and can afford and have it fitted for you. The more comfortable you are on the bike, the more you will enjoy riding it.
This site lists prices of several brands of fat bikes:
This site lists prices of several brands of fat bikes:
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