I worked with a group of students modifying and assembling a BugE. From my experience, this vehicle will weight much more than 98 lbs, will have trouble being registered in many states, will never make it 30 miles, and will cost considerably more than $3,700.
In TN, I think any motorized vehicle with 3 wheels is a motorcycle and will have to be able to keep up with highway speeds. I think. Someone else might comment here. It definitely can't be registered in TN as a low- or medium-speed vehicle because they must have 4 wheels. I don't think it can be a scooter, but not sure there. Actually, I am not sure of the legal status of any 3 wheel trike with a motor on it. As long as it looks like you are pedaling, you are not likely to have any issues, from a practical point of view, but I am not sure it is a street legal vehicle in TN. The BugE, which is a very similar vehicle, is a motorcycle.
The BugE, assembled, will cost around $8,000 by the time it is on the road if you do the work yourself. You can buy one fully assembled for around $10,000. The BugE weights about 350 lbs with the batteries, I think. It is not built of lightweight materials, particularly, so I am sure this can be reduced, but I don't think it can be reduced by that much. In particular, the weight of batteries to go 30 miles will be significant. The weight of the body will also be non-trivial, in particular the seats. Anyway, I think most people here realize this is not a real vehicle.
Finally, at least in the US, the market for this vehicle will be very small, even if it was exactly that the "designer" specified. In reality, the price of gas is still too low for most people to consider a significant change in the way they commute, run errands, etc. It has fallen below $3.00 here. For that price, it would take at least two years to make up the cost of the vehicle. And where are you going to keep it? Without full coverage, keeping it outside will increase depreciation considerably.
After working on the student project, I keep coming back to an ebike as the ultimate in efficient single person commuting for anything less than 10 miles, one way. Even longer if you are a little more hard-core, but certainly 10 miles is pretty do-able by nearly anyone. It has its downsides but it is hard to argue that an inexpensive, high mpg car backing up an ebike isn't near optimal for the average commute. That is my opinion anyway. There are definitely days when I wish I had a windscreen and roof but everything is a compromise and you can't discount that the law doesn't allow just anything on the roads. An ebike is sailing along through a bit of a loophole it seems to me. If they get more popular, I am afraid someone is going to figure out there is money to be made and there will be regulation and licenses and fees of every sort. Right now, you can add an ebike to your commuting picture for virtually no recurring cost so the payback period is relatively short.
I think truly inexpensive weatherproof personal transportation will continue to be frustratingly distant. When you put something on the road that looks like a car, you have to meet certain legal requirements that are going to drive the price up and make the vehicle heavier than it could be. Building a dicey experimental vehicle in your garage is one thing. Mass producing them and selling them is another. You have to be able to defend yourself against the inevitable law suit and that is going to cost serious money.