Nice looking machine you got. The M6 is a great performer. Mine has found me a lot of old coins and tokens and artifacts. If you want to give your machine an advantage, especially in sites that are trashier etc, I would look at getting the Eclipse 5.3 coil to put on it. Almost a must have coil for that machine.
Hi , I payed £325 uk pounds for it from a detector shop s/h
It was a coil cover on it, I could get my thumbnail down it, managed to pop it off and clean it out.
I fancy saving up for a s/h dfx as well now for xmas haha. I really really like the v3i too but a bit prices for me at the moment