Is that an octagon barrel - 10" usually is.
They do kick like heck. I have about 40 barrels and chamberings and the octagon 44 Magnum is pretty high on the "bang - ouch" list. I'd rather do the 375 H&H or 405.
I'll agree with the $425.00 and $500.00 spread, keep in mind the newer TC Contender and Encore don't have adjustable triggers, yours does. You have the catamount engraving and unlike newer models a hammer extender won't (eventually) bend and break the hammer spur. G2 Contender barrels will fit your frame too.
Downsides are the action is pretty tough to open and must be opened if you lower the hammer but don't fire.
I don't recall if the front sight is screw attached, if so it's easy to replace. I'm assuming that under the rear sight it's d&t for a standard TC scope mount.
Depending on which state shipped, you should be able to do it yourself - perfectly legal for you to ship to a receiving FFL. Others may not agree, but it is 100% the buyer's responsibility to ensure his FFL will accept from a mere mortal "non-FFL holder". If the gun shows up bloodstained, covered in hair and brain matter with a note that reads "bury next to Hoffa's body" and the FFL says "no thanks" - it's all on the buyer to resolve, not you.
An alternative is to go to your LGS and have him ship to the receiving FFL. Add the cost on to the shipping. Still, the buyer is responsible for ensuring his FFL accepting.