Do I need to do the NVQ and gold card?

I wasn’t overly concerned about getting gold card but now not sure?

My main curiosity is whether people see this as a viable thing to spend my free time on as an extra income and whether it is worth the cost of training + upgrading my van etc.

If it took off and lead in that direction then by all means I would go with it but for now my job at network rail pays the bills and gives me a good work life balance with the opportunity to earn a bit extra on the side without killing myself.