Hello & welcome from upstate Ny
I know very little of the bounty hunter line and even less about the older models.As far as a machine being to old to use,that would depend on you and what you want to use.If that machine was taken care of and it's all in working order I don't see why you could'nt start out with it,but that's just my opinion.Now most of us are not experts on telling if a machine is performing at 100% so usually most that get older detectors or at least I did in the past is send it in to the company for a once over,that is if they still have parts and still do repairs or tune up's on that older machine.A call the first texas will get ya that info.This is what I would do if I found that I had a older machine and had interest in using it.
Again it's all up to you and what you want to use.Maybe you want to go with a newer or brand new model,do a little research and see what everyone has to offer if you decide to go that route.
I wish ya luck with it all..........................................