So you are looking for a new scoop for beach detecting. Here is a few things that's I have observed from trial and error. Hope it may be of help.
The cheapest and best value for money is to buy them from the Ukraine via ebay.com. They generally arrive within 15 - 20 days.
If you are just doing sand then get the ones similar to the ones in photo on left and right. These are usually about 250mm deep, 200mm wide and 120 high.
If you are doing rocky/sand areas then the scoop in the middle is best. With it's point you can work your way through the rocks etc with less damage to the point of you scoop. These are usually a bit smaller 250mm deep, 160mm wide and 120mm high.
Always get 2mm Stainless Steel. 1.5mm will wear out in no time and 2mm only cost another $10-$20.
Current cost on ebay are around $120-$130 delivered to your door. (Depends on $US/$NZ conversion rate)
You also need to look at the inside diameter of the stem. I always get them between 32mm and 36mm -
the bigger the better. Never get lest than 30mm unless you own a hardware shop.
Also the size of the holes in your scoop. I like them to be around the 10mm as I then don't drop chains and small bullets etc quite as much. You may prefer bigger. Down side of 10mm is that you have to do a bit more shucking to get rid of sand etc. That's a price I'm happy to pay.
One thing that you will need to do after a while is get someone to weld the support braces to the stem. The tend to only weld on one side and not both. I've had the odd seam go as well. (but still worth it)
Wooden handles - for me they only last 40 hours even if oiled, greased etc. I now prefer fiberglass ones. Cut off a couple of the knobs and file or grind to a tight fit. Drill in a fixing screw. The first of my fiberglass one I broke around the 100 hour of use mark but found if you put a stainless hose clamp around the top of your stem, this helps. Have not broken a handle now for around 18 months - for me that's about 600 hours. I like the looks of the carbon fibre handles but cost and scoop stem variation are putting me off at present.
You need some floatation. I cut about 200mm on swimming noodle (I think it called that) Look in photo.
Then just tape around and it lasts forever. This keeps your handle upright in the water. Also I drill a roundhead screw into the top of the handle facing me so I automatically know by feel which way my scoop is pointing before I dig. Essential when you are up to your shoulders in water. Some people like to add a lanyard to top of handle also.
You will notice the wear on the scoop on the right of the photo. This is just wear and tear after 400 hours. Had it re-built, but they still wear out. (the last re- build cost more than the scoop delivered) Mind you I do drag my scoop.
When working the scoop in the sand, don't just dig it in and then try to lever it out. Work the handle sideways and small levering up and down to break the suction. With a bit of practice you will find both your scoop and handle will last a lot longer.
Well that about all I can think of at the mo. Hope it may help someone.