When I first started looking for a kart, I wanted something that had good field size, was local (within an hour drive) and was affordable to me. I had a newborn at home, a wife that essentially quit her job and was doing well enough at work to put a little extra aside every month. I did some research and at the time TaG was hot. Boasting the largest fields next to shifter, but still with in my budget range. LO was barely a blip on the radar at the time and the fields were dismal.
Little did I know that within two years of purchasing my kart that the LO fields would blow up in my area and that TaG fields would dwindle. LO was an option, but very little was available second hand and the deals were better at the time for TaG. I had driven a 4T a decade prior and it was fun, but I felt it lacked the power of a 2T (power vs weight).
Back Story: Years ago, my brother and one of his race crew buddies took me to a huge warehouse in the middle of nowhere north of Atlanta. It was a rental kart facility unlike any I had ever seen. Forget the bulky surround bumpers and bodywork. These were Race Chassis fitted with Honda 390’s modified to run on Propane for indoor use. They were light, they were nimble and they even had decent pull out of the corners. What they didn’t have was Scream! Like the kind of scream that you get when you are barreling down the straight so fast, that you question if you can put enough brake on to slow the kart without locking up the hard tires on a slick track and not completely blow the corner. I never really felt that. Anyway, Andretti Speed Lab came along about 5 years later with their purpose built tracks and put these guys out of business. Sad really. I think they were just a bunch of racers looking to put something together to share with the world.
Okay, back to my point in all of this. I skipped LO for TaG. At the time, I thought I could have a higher learning curve with more drivers in my field. To a point, I did. Where I failed was a combination of lack of seat time due to my work schedule not lining up with the race schedule and the higher running costs needed to stay at the front of the field or at least improve. I was and to some extent still am a budget racer. At first I would buy a set of tires, run a race, then a couple of practice sessions and try to race on them again. Being new to the sport, meant chasing setup was challenging. I was not about to spend $ on new tires every race. I did what I could and bought a new set of tires every other or every 3rd race. In between, I would buy a set of take offs from the local shop and use those for practice. At the time, a can of spec fuel was around $75 and oil mix around $15. Now fuel has climbed to $100 and oil $20. Keep in mind 2T burns through fuel twice as fast as 4T. Other expenditures are not that far off from LO other than you may go through sprockets and chains faster due to the higher revs. The expense is manageable, but still higher.
Like James said, you sort of have to figure out what your budget to fun quotient is and decide from there. In my area, many of LO guys have moved to 100cc. The budget is somewhere in the middle between TaG and LO. Generally the same tires, just the added expense of fuel. They run close times to the TaG class and should considering the far lower weight they can run at. For me, that is not an option. I am too large of a person to ever make weight in 100cc. I am already overweight in TaG and struggle to maintain mid-pack with the occasional podium with ZERO LEAD on my kart. One guy, near my weight is consistently up front, but he is just stupid fast anyway. Congrats on the win today Kyle. I still got 3rd! 
Give it a try and see what you think. You can always go back. Bonus fact, as your brain learns to process at the faster rate, if you do go back it will feel like you are racing in slow motion! Happens every time I get in a rental.
