(edit: looks like David and I were writing our replies at the same time.)
Hi Bill, I do hope you join us at the track and talk to a few people. Folks find a way into the sport at a wide variety of budgets. Being just one step down in performance from shifters, TaG karts and parts can be pretty pricy depending upon age and quality. The rental prices you quoted are fair and common for a TaG kart. The $150 is a disincentive as much as anything. Nobody should ever be driving over their heads. You learn, you get faster. Nobody gets faster wrecked. Google suits and helmets, or just click an ad on this site… the prices aren’t near what you think.
Walt makes a good suggestion about the Briggs 4-cycle karts. Much less expensive than TaGs to buy and maintain. Not as fast but tons of fun. The NHKA doesn’t have a clone class or an adult LO206 class. That’s because they are about the same speed/power as rentals, and there’s plenty of rental tracks around here. We run the WF instead, which is similar to the LO206, but twice the power. You can find very good used complete WF karts in the mid $2k range.
Come to the track. Ask around. Folks will try to help you find a way in.