Earlier quoted context omitted.
If you look at dollar and time amounts, all financial interactions are pretty much zero-sum.
The transaction itself is not zero sum. The existence of the transaction itself is proof that both parties value what they received more than what they gave away (otherwise they would not have transacted). The waste of time is having to haggle to arrive at the price, when the price could have been published. It benefits nobody, because that's the price the transaction would have happened at anyway. But we have to do…
Honestly, thinking that there should be fixed prices for everything, if you're a rich westerner going in, means you're trying to externalize the effort of setting a market clearing rate, and trying to piggy-back off of the locals. If it's at some multinational chain, then sure, don't have people haggle with you over the price of some McNuggets, but at a family owned business, if they can get an additional 20% of the price of the goods they might be doubling their profit margin, so why wouldn't they haggle?