I always knew the rip offs were very simple with 70s or so tech....

I always knew the rip offs were very simple with 70s or so tech. Good point you raise about a possible replacement cycle occuring.

Their marketing sounds great - if you are a prospector - you would have to buy one:

GPZ 7000

The Future of Gold Detection is Here!
“I revisited an old rich patch today where previously I couldn’t work the ground because of noise and instability. With the GPZ 7000 the difference was staggering. The gold started to come in nice and steady with a haul of 30 grams at the end of the session. The biggest nugget weighed in at 12 grams and was 17 inches deep.”

“I managed to find some decent gold at depth, including a 2 ½ ounce nugget at over 2 ½ feet. A GPX 5000 with a 20-inch Monoloop couldn’t even touch it.”
Jonathan Porter, Australia

ZVT technology goes to the NEXT LEVEL for all serious gold prospectors, providing substantially improved depth. No longer will you be limited to using either sine wave continuous VLF transmission detectors, that struggle in mineralised ground, or square wave PI transmission detectors, that can be insensitive to varying gold sizes and compositions.