Are you looking for a collector or a driver? An 84 would be a real collector's item if it's in good condition - 1st year of the 4runner, solid front axle, etc. To a collector that could be a good price. :shrug:
OTOH, as someone who owned a 22r powered, SFA Toyota (my first new vehicle, an 85 Hilux pickup, bought new in May of 85) I can tell you I wouldn't pay that much for one.
I think sometimes the internet magnifies the perceived value of older vehicles, and they kind of acquire a "cult status." Sometimes younger people think older vehicles were so awesome because they never actually owned one and had to put up with its deficiencies.
The simplest answer to the question is it is worth what someone is willing to pay. If you're one of those people who would pay $4500 for a 30 year old 4runner, then I guess it's worth that. FWIW I sold my 1999, tall coil, E-locker equipped 3rd gen for $5000 about two years ago, so there's no way I would pay the same amount for a greatly inferior vehicle. But YMMV.