Careful shopping will get you a new model Win 86 for not much more than the msrp on a Marlin.
They are of course two entirely different rifles. The marlin is nothing more than the 336 action adapted to take 45-70 cartridges and thereby allows the top mounting of a scope.
The 86 is a continuation of the original design with the addition of a tang saftey.The 86 will handle 500 gr bullets with ease, the Marlin maybe not so much unless using specially designed deep seated bullets. Top mounting a scope requires the use of a scout scope. But the 45-70 isn't necessarily a scope required cartridge and a good reciever sight will serve well. The 86's do stand head and shoulders above the Marlins in fit and finish, and that will account for some of the price difference.
Just look at your 92, imagine a rifle about 3lbs heavier with the action long enough to accept cartridge length to 2.8 inches and you'll have a good idea what you're getting into with an 86.