They way I see it, it doesn't matter what sport you go for, you have to spend money, if you take up shooting, you have to buy a gun, not cheap, archery your bow and kit etc,
The dearest kit you need to buy for ferreting is the locator but once you have it, and look after, it should last for years.
I have a mark1 which must be over 30 years old and still going strong. good bit of kit for a learner, teaches him to locate the rabbit with a dig, the more you use it, the more confident you become, and you should know where your ferret is underground, and save you a lot of waiting which can be a