By legal, what do you mean exactly? Bartering is still perfectly legal, always has been and always will be. If you wonder if people will resort to it more, yes, it’s already happening. But money came about because things got too complex. It was one thing when societies pretty much just had food and clothing for needs, you had one person who could make clothes and another who could gather or kill food, you’d trade with each other. But there are literally billions of things people need and want in our society and bartering is not, nor could it ever again become (without a complete break down of our society and a massive cleansing of the population through disease, war, the rapture or some other method) a viable means of people trading one skill for another. No one person who would require the things I would be able to provide out of whole cloth could possibly meet every one of my needs, therefore they need to give me something for my efforts which I can use to seek out providers of each thing I need…such is what money is about. Even countries which experience bad problems with their monetary systems….first off their banks will declare bank holidays, take back all the old money and put into circulation new money (for example, you have hyperinflation, you don’t want to have to carry around a 1,000,000,000,000,000,000 bill to buy milk, so the government will make 1,000,000,000,000,000,000 in old currency equal to 100,000 in new currency and have you bring your money in to trade. Or in some really depressed countries where money becomes next to worthless, what they have often done is to use another currency…like people in certain countries will only accept Euros or US dollars, even though they’re not the currency of the nation in which they live…it’s a hedge against the declining value of a dollar.
But this has never gone away and will only get more and more popular as people have less and less money to spend, even a few years ago when things weren’t nearly as bad as they were now, my wife joined an internet service allowing people to swap books…you’d put books on that you had, and if someone requested one, you’d ship it to them, you’d pay for the postage, but you’d get so many credits for that book. Then you could take that credit and have someone else send you a book off their list. But even that form of bartering required sort of an intermediary, something akin to money (in this case, credits). And what about that guy a few years back who decided that maybe he could trade a paper clip for a house. He wanted a house, so he took a paper clip and saw what people would trade him for it. He picked the best offer, then traded that for the best thing he could get, and so on, and so forth…I think eventually he got a walk on role in a film, and someone really wanted that and they traded him for a house, or something for which he was able to trade a house.
I think it will become more of a necessity for some people, but cash will ALWAYS be king.