After 26 trips in 20 years I've experienced the gamut of higgler interactions. After a couple trips I developed a strategy. Every 100 yards or so, stop and befriend a vendor. Buy a little, chat a little, maybe buy them a beer. Eventually you have a network of friends that tend to watch out for you in their territory. I have good friends that I met that way on my first trip that are still friends to this day. I know this approach isn't for everyone, but it works for me. I think a lot of it is attitude. The first thing I tell newbies is be careful what you wish for, Jamaica has a way of answering.
