The 93655 is a great jack. If it's in really good shape and no leaks, especially if it's been recently rebuilt, then it's probably priced fairly, especially if you could negotiate the price down a bit. If it's leaking or needs work then I'd definitely walk away for that price.
The cost to have the hydraulic unit rebuilt for you on a 93655 can run from ~$200 to upwards of $300 on that jack. A seal kit to do it yourself would cost $60-$80. Once rebuilt you got a jack that might go another couple decades or longer.
Hein Werner (formerly Walker) doesn't sell the 2-ton any more, but they do still sell the 4-ton just like it - same long chassis frame & IIRC I believe the 93655 can also fit the 4-ton hydraulic unit with little to no mods. Today the 4-ton
Hein Werner HW93657 will run you well over $1000 new.