Condition, condition, condition.
Condition is everything when buying old guns. It is impossible to give a unseen value. I would not bid on it unless I have the chance to handle and inspect it first.
The 32-20 is my favorite cartridge. However the expense of factory rounds and the lack of stores that stock it make it a reloaders cartridge. Contrary to what you may heard or read, including here on THR, it is not a hard cartridge to reload. The bottleneck case requires some extra care when sizing so you will not reload a high volume of rounds quickly. Brass is easily available along with bullets.
But for me I will not give more than $400.00 and it would have to be in excellent condition. The Army Special is not a particularly comfortable gun to shoot.