Do I want a trailer jack for my little trailer?

I'm buying a small trailer, only 4' x 8' bed, the one that folds in
half sold by Harbor Freight and NorthernTools (I'm not saying they're
the same, but similar). Buying it new, with new tires.

And they push accessories such as a trailer jack that holds the tongue
up when it isn't resting on the trailer hitch. Do I want one, do I
need one, for a trailer that weighs 200 pounds on which I'll put less
than 100 pounds of furniture? After all, I'm supposed to put the load
on so the tongue weight is no more than 50 pounds, right? And I can
lift 50 pounds easily. OTOH, I love accesories and gadgets? OT3H, I
will rarely if ever use it, but I will pay for gas to carry it around
with me whereever I go.

In fact, I plan to use the trailer only once, to go from Dallas to
Baltimore, and I don't expect to put the trailer on the hitch more
than once, or take it off more than once. At the start and at the
end. Since I have no place to keep the trailer, I'll have to sell it,
cheap. So should I buy the jack?

Should I buy a spare wheel, tire, and spare tire carrier, for a total
of 40 dollars? I'm not made of money.