Six months on, neither has been proved right. Trade over Christmas, the most lucrative period in the bookselling calender, showed that it takes more than low prices to sell books. Publishers that were first in with the reductions failed to find their mass market, and many failed to lift sales enough to break even at lower prices. Small sellers, which couldn't afford to cut, emerged from the Christmas price wars intact with barely a dent in their sales. Surprisingly, it seems, for those who brought down the NBA, the plot has failed so far.
"Last summer's surge in paper prices knocked the operating profit out of a good many publishers," explained one analyst. "They saw NBA as trapping a mass market and thought that its removal would permit a sales surge. This didn't happen."
Publishers Reed and Hodder Headline were the first to bail out of the NBA and slash cover prices in preparation for the Christmas rush. In early January, Hodder issued a bullish trading statement announcing a sharp sales increase, suggesting that its mass market had indeed arrived.
But these publishers, at the front line of the price war, had cut margins to razor-thin levels, and the extra sales failed to compensate. By March, Reed Consumer Books had seen its operating profits fall by 60 per cent. Hodder Headline, despite a sales jump of 10 per cent, saw pre-tax profits fall by 30 per cent.
Willie Andersen, managing director of the Glasgow-based chain John Smith Books, believes that companies which relied on slashing cover prices to recover sales had a primitive understanding of the book trade.
"They just don't have a clue," he said. "If a book's drivel, it's going to be drivel at whatever price it's at. The public aren't so gullible as to be taken in by these gimmicks; they're only going to buy a book that's worth buying. If you reduce the cost of a book, its sales are not automatically going to shoot up."
Alan Giles, managing director of Waterstones, argued that a marketing strategy based solely on price cuts mistook the complex nature of the trade. "When people are buying books, price comes as a secondary consideration," he said. "We only discounted 50 titles, and the sales response was mixed."
Supermarkets, in the strongest position to "stack 'em high and sell 'em cheap", have been noticeable by their absence from the market. Early fears that they would double as warehouses of cut-price blockbusters have been allayed.
"The most important result that's come out of the NBA collapse is that supermarkets don't seem to be taking an interest," said Mr Andersen. "You can see they're not sacrificing any of their ketchup space for books."
Delia Smith, with her winter cookbook, found herself unlikely ammunition in the Christmas price war. Her cover price, pounds 16.99, was reduced to pounds 9.99 - it was by Delia that bookshops would stand or fall.
It was only when London bookseller Graham Davies found himself selling hundreds of Delias at the full price that his fears for his bookshop's future subsided.
"After the NBA collapse, we were very, very nervous," said Mr Davies. "We make most of our money from best-sellers, so I couldn't afford to offer any reductions. But even at the full price, Delia was a complete success. It shouldn't have happened, but it did."
Mr Davies's customers evidently decided not to shop around. "We didn't know exactly how important price was going to be," he said. "In the event, our customers stayed loyal, but that probably won't last forever."
So until price becomes the dominant factor in book sales, the future of small bookshops seems secure. The Booksellers' Association has noticed no increase in the number of sellers shutting down, adding that the NBA is a relatively small threat compared with the growth of book chains.
Distributors, for whom closed bookshops mean bad debts, say they are no more concerned than they were last year.
But the book world moves slowly. While price wars have not taken off in the first round, there's still time for things to fall apart, as Mr Giles admits.
"At the NBA collapse, people's main fears were that price cuts would edge out first-time writers and marginal titles from the market," he said. "That hasn't happened so far, but things take time. I'd say that the jury is still out."