It would be an incredible buy, but it's not complete. It's only the readout -- the part that actually gets the information, the "transducer," isn't included. It's kind of like buying a monitor without a computer.
Damn -- I really need a fathometer. Mine is broken, and I found the bottom TWICE on Sunday!
I bought one of these with the nylon through-hull transducer. I got it online at StarMarineDepot.com for $97. Looks like sailnet has better pricing now. There are also options for in-hull and transom mount transducers, which one you want depends on your situation.
I have the thru-hull transducer installed, IIRC it is 2" in diameter and fit in the existing hole in the hull where the old transducer was. I hooked it up to test it and it gave a readout, but I have not finished installing the display onto the cockpit bulkhead. If you don't have a pre-existing transducer hole and don't want to drill holes in your hull then get the in-hull or transom mount version. The transom mount version is not generally recommended for sailboats, I'm not totally sure why, and the in-hull may not work if you have a cored hull.
The instructions for mounting the transducer are clear and the wiring is simple, but YMMV as it will depend on where you want to put the transducer and display and the wiring setup of your boat.