Today and tomorrow, you can get the Badlands 9k winch for $225... not much more than that come-along.
Harbor Freight also has an 8k come-along for $30.
My only concerns with using a come-along are:
1. You have to manipulate the lever very close to the tensioned chain/cable/strap and you're in serious danger of injury if it snaps. One reason I think that the HiLift has an advantage.. it's heavier and will pull the cable down more if it snaps and the actuating lever is longer so you're not as close to a breaking cable/chain/strap.
2. If you're vehicle is really mired down in the mud or your trying to pull uphill or over an obstacle, you are going to be straining your body to move that winch line.
It's all in personal preference I suppose... to me a HiLift (which I have) or a winch (wished I had) are a bit safer and easier to use when recovering a vehicle. They're also easier to store, outside of the Jeep, where space is already at a premium.