We want to mostly use it on land, but be able to use it in the river as well. We may get two (one for each). So one can be a little less expensive. I would say no more than $800.
I was thinking about that with the used ones, but my friend wanted me to ask.
If you want to do land and river (even submerged) detecting, the Nokta Legend, Nokta Simplex, Equinox 700 and Equinox X Terra Pro are all good options. The XP ORX can be submerged but that would require an antenna to transmit the wireless signal from the coil to the control unit and a protective waterproof case for the control unit. The Legend and Simplex have proven themselves to be waterproof as advertised by Nokta. The Equinox 700 and X-Terra Pro have newer control unit designs which are supposed to correct the leaking problems of some previous model Equinox 600/800s.
Hunting on land in your area may require a detector that can handle a lot of magnetite (iron ore), volcanic rock and salt mineralization. The Legend and Equinox 700 have simultaneous multi frequency operation options that can really help with ground balancing, depth and target ID accuracy in those conditions. From experience, the Simplex will drastically up average 3" deep and deeper lower conductive targets like small aluminum foil, small aluminum shards, pull tabs, small lead, small brass, US nickels and small to medium sized gold jewelry up into the silver range of target IDs due to higher mineralization. The Legend and Equinox using their multi frequency settings will not up average those target IDs nearly as much even on deeper targets. The X-Terra Pro may up average quite a bit on those targets. The few videos I have seen so far do show this happening on deeper low conductive targets.
If you are able to just dig everything then that doesn't matter so much. If you can't physically dig it all or if there are restrictions on digging with a shovel as in you don't want to completely ruin someones yard or public park, really accurate target IDs and tones may be very important.
Even though the Simplex and Legend are both made by Nokta, they have very different sounding audio, tone choices and very different target ID ranges so just be aware.
The Equinox 700 and the X-Terra Pro have very similar audio, tone choices and ID ranges so they would make a very good pair of detectors. The Legend is so similar to the Equinox that I would also recommend pairing a Legend with an X-Terra Pro.