I'll give you two answers.
First one makes sense - medical knowledge or first aid skills. That kind of ability can always be traded and is always helpful :-)
NEXT, some advice from a guy who WAS in the collapse of the Soviet Union. He was a Russian, and I read his comments years ago. I really wish I had saved the Web site where he published this stuff, but it's probably gone by now. Here's what he said ... "Buy a Russian refrigerator. The best advice I can give you is to buy an old Russian refrigerator.".
So what the heck does that mean?
Well ... apparently the old Soviet refrigerators were big heavy clunkers. They were not terribly efficient. But it was pretty easy to take them apart, replace parts, and keep them going. So Russians developed a whole black market for refrigerator parts ... just to keep these clunkers operating. And so what this Russian guy was really saying is that it's better to have appliances that you can repair easily, even if they are not the most fantastic devices.
Here in the USA we have built up an entire culture of hardware where "if it's broken ... just throw it away". That mentality worked because we had the upper hand economically, and all the throw-away stuff was made cheaply in China. But that whole philosophy is going to collapse ... if the US economy goes the same way as the Soviet system.
Actually, the primary economic force driving the concept of disposable appliances was the increasing cost of labor versus the decreasing cost of off-shore production. With insurance and overhead tacked-on, a small appliance repair organization needs to charge at least $70/hour to be viable, and has to tack on a margin to all parts they order to cover shipping, shipping damage, handling defective parts and other overhead.
A secondary influence was the cost of the logistics to ship parts, particularly large and/or heavy items such as motors and compressors, from the off-shore manufacturer to the US warehouses and then distribute them on-demand to local service locations. The warehouses themselves are expensive to maintain.
The final nail in the coffin was in the 1980's most corporations looked to profitizing their parts and service chain in order to be more competitive on original purchase price. Before then parts and service was at-best a break-even operation, usually a cost center written off as part of the customer service/warranty operations. Today that operations contributes to the company's revenues and, in most cases, it outsourced to third party service providers operating under forth-party insurance programs. Labor-wise this is more efficient, but overall the cost to the consumer is increased by high repeat service call visits and appliance down-time waiting for parts.
Small, independent appliance repair centers had difficulty competing in this environment and in most places shut their doors, leaving a market almost monopolized by national chains. Local appliance retailers, who often had their own factory-certified repair techs, were replaced by big-box stores and big department stores.
Today if you want to find a bargain on appliance repairs you need to look for small dealers of primarily used appliances in lower-income areas. These niche stores buy used/broken appliances and strip out all the usable parts to repair their customer's appliances and are masters of improvisation. You might wind up with a Whirlpool compressor in your GE refrigerator, but your food won't know the difference.
But anyway, large appliances are still repairable. Interruptions to manufacturing or economic collapses could easily tip the scales back to favor repair versus replacement. Knowing how to repair the appliances, particularly how to adapt parts from dissimilar manufacturers, would be a very useful skill to learn. Establishing a network of parts suppliers, or acting as a parts recycler, could also be useful in difficult times.
If you are concerned as a consumer, your best bet is to buy the simplest appliances you can find. Favor mechanical controls versus computerized/digital controls. If you can afford service-industry level appliances, such as used for restaurants, hotels and commercial laundry services, these tend to be more durable and easier to repair/maintain than those designed for residential use. But also look into appliances made for RV use, as these are also usually simple and easy to maintain, as long as you have access to the electronics. But even electronic controls can be converted to manual operation if you have sufficient knowledge of electronics and how the appliance operates.