You make a very good point. However...if you buy a second-hand car do you replace all the seatbelts and airbags?
Nope, but if I had to replace the seat belts on a second hand car I would'nt buy another set of unknown second hand belts. Airbags are a fit and forget non-regular use safety item. Same with crash helmets. Go cheap, secondhand and take a risk? Of course it's always personal choice, personal risk assessment.
you do raise some very good points....i have been made aware that there are some copies out there so probably very good advice....thanks. I was leaning towards new and you have probably swayed me over the line
No worries, ultimately it's your choice of course. Yes, the harness market has been infiltrated with some cheap and unsafe copies and it's well documented. The trackday harness, seat, roll cage combo always generates some debate with lots of fixed views and eventually you have to set some limits on how much perceived safety you want. Just when you think you have the balance about right you'll come across the HANS, plumbed in fire ext, external cut off etc type advocates. My view, if you are going for a specific level of safety kit, get the best you can afford and don't compromise with unknowns.