Don't neglect to look at the Garrett Sea Hunter Mark II. It is in your price range, performs every bit as well coil for coil as the Sand Shark (if not better), and has several important features the Sand Shark lacks:
The Sea Hunter allows you to switch coils. The Sand Shark is hardwired. You can go 8 inch or 10 x 14 inch with the Sea Hunter. The difference in size between a round 10 inch coil and a 10 x 14 might not seem like much, but on a large beach, the difference in sand coverage is enormous. The Sea Hunter coils also offer much less water resistance than the SS coils. Take a look at the pics of the two detectors to see what I mean.
The Sea Hunter's battery compartment is completely separated from the rest of the detector's electronics. Unimportant? Have you ever tried to switch out batteries on a stormy winter beach hunt on a Sand Shark? You have to open the entire machine and to remove the battery pack, exposing the machine's internal components to moisture and sand infiltration. Not good.
The Sea Hunter's standard search mode is
almost a true no motion mode. This is a big advantage when trying to pin point in the surf or underwater. The Sand Shark requires a significant amount more coil motion in order to continue detecting. In other words, it detunes over the target faster. This might not sound important, but when you are struggling to stay upright in chest deep water trying to pin point a target...it will be.
The Sand Shark has hard wired headphones. The fact that the coil and headphones are hardwired makes the machine awkward to store and transport...and also tends to place the detector's wires under more stress which can contribute to wire fatigue and detector failure.
Quite a number of professional salvage outfits---including the Mel Fisher group---utilize the Sea Hunter as their primary underwater detector. I am not putting the Sand Shark down, but I have never seen or heard of a professional outfit that uses the Sand Shark.
Which brings us to the Sand Shark's "life-time warranty"
Is it really all it is cracked up to be?
If you use a detector a great deal over time, the electronic components will begin to degrade. The performance of the machine will decline, even though the detector is still operable. Tesoro will NOT replace the unit when this occurs. Trust me on this one. I have an old Sand Shark and all three of the round coils manufactured for it. I used to use it a lot and it is just not nearly as deep as it used to be. It seriously struggles to find a nickel beyond the 6 to 7 inch range in the wet salt. I have sent it to Tesoro and they say that it: "tests to specs" and that is that. They will do nothing to get it back to the detection range it had originally, which was quite good for a machine of its design vintage.
Incidentally, here is a link to a Garrett Sea Hunter find by another member from a few months ago:
http://www.treasurenet.com/forums/today-s-finds/355763-does-coral-beep-yes-when-its-full-coins.html