I concur with the other posters in the main. Except, as we all know, money in the bank loses its value over the years. You can't go pigeon shooting with a bond or a savings book.
If you have what you need to live on, spend your extra cash on a good gun in good condition and you can use it until you need to sell it. You may make a profit, you may just get your money back. But you will have been enjoying that money in the gun for all those years - something you don't get from a pile of cash.
I have said it before - buy a Purdey for £15,000 use it for ten years and sell it for £15,000: you just had ten years' rental of a best London sidelock for $0.00 per annum. Now if they were advertising that rate at the local gunshop we'd all be in the queue!