I see that Amprobe has several models of the AT series 2001,2002,2003,2004,2005. do you need all the bells and whistles or does the AT 2001 have what you need?
I went with all the bells and whistles.
I bought the AT-2005 model and have no regrets.
Usually I only have regrets when I try to be cheap and end up wishing I had spent more.
I use this tool a lot and have found numerous hidden splices behind sheetrock.
Other contractors have told the homeowner that they would have to start tearing out sheetrock until they locate the problem.
Charge a flat fee for locating the problem and include enough in the fee to pay off the tool in the amount of time you feel comfortable with. If you charge enough, your customer's are paying for the tool not you. After all you're saving them a lot of money by not digging up their yard or tearing out a bunch of sheetrock.
Once the problem is found you can then give them a price for the repair.
In the case of the cable I show in the picture my price was for installing a new line in conduit buried to the correct depth.
The landscaper and the homeowner weren't too happy when I told them the freshly landscaped yard would need to be dug up for this to be done properly.