in college i was thinking about opening up the same type of business, but catering towards drag racing and street racing. In order to even have the chance of being successful, we were looking at $300,000 minimum with the current business model we had come up with, assuming $0 income for 10-12 months (which, in all reality, is how you should set up any business model). And we didn't need near the amount of high dollar fabrication tools that an off-road shop would require. It entails a lot more than the Average Joe thinks about, trust me.
For instance, have you done research into opening distributor accounts with companies like RC, RE, etc.? Typically they require $5,000-$25,000 just for the RIGHT of being a distributor. To get around this, you usually go with a multiple-line distributor. Not sure who does it for offroad, but for the racing community, it would be Arrowspeed or Summit, and for the motorcycle community it's Parts unlimited and Tucker Rocky.
With these companies, you can get pretty much whatever you need for a customer through them, whether it be anything from a headlight, to an axle, to a tub. You don't see the discount you would see by opening an account directly with the manufacturer, but you also don't need the capital required to open an account with the manufacturer. I know when i was talking with Summit and Arrowspeed about starting an account, they require about $1,500 (IIRC) to open an account, but Arrowspeed was going to waive the new account fee if i signed a contract stating I would carry at least $2500 worth of merchandise in the shop at any given time.
Bottom line, if you ever plan on being any more than successful than just having a status-quo shop in Greenville, it's going to require several hundred thousand dollars. I can tell you, having been to A/T Fab and seeing the tools and equipment they have, not to mention the 400 sq ft office/ showroom, and the +-4,000 sq ft shop, they have probably upwards of $750,000-$1 million dollars invested in that place.