- Gas mask. If you absolutely NEED a gas mask, you will already know this and probably be issued one. In order for a gas mask to save your life you need to carry it with you 24/7/365 because they only work if you can put them on before you are exposed to a toxic nerve agent. For biological agents, you will probably be exposed long before you even think to use the mask.
- Night vision goggles. Seriously? Yes some new preppers somehow put these on their list of stuff they need. Again, if you actually NEED them, they would have already been issued to you. There are dozens of things new preppers need before they spend thousands on this sort of gear. An emergency fund for starters, a month's worth of stored water, six months of stored food, quality outdoor gear... I like cool/fun gear as much as the next person but getting the basics together first is way more important than having the flashiest tactical gear.
- A .50 Desert Eagle or other fancy firearms. You need a set of firearms (pistol, shotgun, rifle) that are of high quality, and that you can run a couple hundred rounds through each month. Once you have all of your debts paid, money saved, and enough food, water, and supplies to last you a good year, then you can spend freely on fancy fun stuff.
- A $500 tactical medic kit. First aid kits should be built up along with your skills. A lot of first aid kit items--meds, syringes, ET tubes, etc--actually expire. You don't want to spend a lot of money for a bunch of stuff you don't know how to use and that will need to be tossed before they ever get used. The more medical education and skills you have, the more stuff you can reasonably carry in your kit.
- Gold and silver. Have you ever handed over a gold ingot to a cashier to pay for your groceries? Yeah, I haven't either. In a disaster you need food, water, gear, and supplies. Money is good to have too. Gold and silver? Not so much. It's heavy, you need to protect it, you need to bring it with you, you need to find someone who will exchange it for whatever you are trying to buy with it. There are a hundred things you will need before you will need actual precious metals. Not that people shouldn't buy gold and silver, I have some myself, but it's usefulness during 99% of the disasters you will likely face is negligible.
- Ultra high-end gear. Do you need a $350 backpack or a $700 sleeping bag? I know people who have this sort of gear, mostly they are the sort to head off to Patagonia or some other far-flung place to hike up very big mountains. Like your medical kit, your survival gear should increase in quality and price as you can #1 easily afford it, and, more importantly, #2 have the experience using such gear to determine what it is you actually need. If you have a family of five and have just started prepping with your little bit of discretionary income, you need to buy gear you can afford (five deeply discounted, good enough sleeping bags from SteepAndCheap) and gear that you will use regularly (like on family camping trips). The more you use your gear in actual survival-type situations (like camping and backpacking), the more you will be able to determine what stuff you actually need, what features you like and dislike, what brands you favor, and what items are worth spending more money on.
So there you have it. Start with the basics--food and water, get an emergency fund together, educate yourself and get the training you need in order to make informed decisions--and then move forward with the more expensive and specialized survival gear that is "nice to have" and not "have to have".