Precious Metals – Investigate this for yourself, but I find the arguments and historical track records against fiat currency and the current rumblings of Government wanting to take care of your investments for you very compelling. Gold is easier to transport with the high cost to weight, but you might have problems cashing a gold coin for a tank of gas. Silver is where I have chosen to invest in precious metals.
The government has repeatedly stated that there is no need for alarm, and that it expects to strike a deal soon with the European Union. An agreement would probably invoke a “standstill” transition period, during which few Britons would notice any changes until December 2020. The European Union says it, too, wants a deal, and it has made positive noises lately, though talks over the weekend failed to produce a breakthrough.
Regarding the general category of water purification, you have essentially combined reverse osmosis with UV disinfection PLUS the necessity for solar and/or gas generated power. Take away the essential electrical power and you still have to boil your water. If you do the math, you could invest up to $2500 for your version of water purification. That’s a “big ticket” indeed. Once again, there are abundant information sources that provide instruction for long term water purification that cost far less.
If the day of reckoning stretches on beyond a few months, however, the ability to grow one's own food will become paramount. Seeds and gardening tools, therefore, should be on everyone's doomsday supply list. Opt for so-called heirloom seeds. These seeds yield disease-resistant crops that produce yet more seeds season after season, unlike hybrid seeds used for mass-cultivated, commercial crops, which can develop into sterile plants.
Obviously, solar panels by themselves are quite useful things to have, and since both Broadwing and Ned in the comments suggested that Goal Zero is quite overpriced, I’d be remiss to leave out mentioning another, more price-sensitive option. Ned recommended Aukey as a brand that makes solar power equivalents to Goal Zero gear for far cheaper. In his words, Aukey “make the exact same thing for a fraction of the cost.”
Hate to break it to you, but your dog probably has a better chance of making it through a total societal collapse than you do. A quick Internet search of "dog survives" lists everything from drowning to being shot, from bear attacks to war -- whereas the closest you've ever come to "surviving disaster" is getting your wisdom teeth pulled, and even then it was only with the help of a cadre of trained medical professionals and a carton of the strongest painkillers on Earth.
Perhaps the most unusual thing about the female prepper lifestyle is that it suggests a counterintuitive movement through time: a return to a slower, more elemental way of life, one that eschews the conveniences of modern consumer society in favor of the empowerment that comes from doing things yourself. Some of the women I spoke to said being a prepper helped them carry on the same old-fashioned life skills — like gardening, canning, and smart budgeting — that helped their mothers and grandmothers during the Great Depression. Others harkened back to the homesteaders of the late 19th and early 20th centuries, whose pioneering settlement and cultivation of the Great Plains form the backbone of the American myth of self-reliance.

The Missouri Information Analysis Center (MIAC) issued on February 20, 2009 a report intended for law enforcement personnel only entitled "The Modern Militia Movement," which described common symbols and media, including political bumper stickers, associated with militia members and domestic terrorists. The report appeared March 13, 2009 on WikiLeaks[88] and a controversy ensued. It was claimed that the report was derived purely from publicly available trend data on militias.[89] However, because the report included political profiling, on March 23, 2009 an apology letter was issued, explaining that the report would be edited to remove the inclusion of certain components.[90] On March 25, 2009 MIAC was ordered to cease distribution of the report.[91]
Personal defense items – such as rifles and heavy firearms – are going to be increasinly hard to manage the farther you move from steady supplies.  Ironically, it’s firearms that help acquire more food, provide personal protection, and deter others from attacking.  In a SHTF scenario, heavy armament is only good within fortified areas.  If you want to stay highly mobile, switch down to a .22LR polymer rifle such as the Savage survival rifle or similar.  Lightweight, collapsible, and perfect for hunting game.  Loaded with subsonic rounds, it can also be a lot more efficient than heading off a target with a loud 30-06.