Beware the Bait and Switch

Bait and switch can refer to a number of things, such as jobs and shopping, but it always refers to fraud. Recruiters may use bait and switch when they dangle a cushy job in front of someone only to change it at the last minute. It's also commonly used in Peru when shopping at the markets or buying something off someone on the street. I've known plenty of people who have fallen victim to this trick both in Peru and elsewhere. Here are some tips to help you avoid the bait and switch trap.

From http://www.findingbetteragencies.com/category/agency-search/page/16/

Take your time. Sellers who use bait and switch try to get time on their side and have you rush. When you rush you're not paying as much attention. Beware of people who want to make you rush.
Refuse a bag. Bags can hide a lot of sins. If there's no bag it's harder for the seller to hide anything.
Buy from reputable people. I love shopping at markets, but some people hate it. The noise, the sellers hawking their wares, etc. However, if you can build relationships with the people you buy from you'll find it can be a great experience. They might give you discounts or the latest and the greatest. Ask other people who they buy from and keep going back to people who give you good deals and good items.
Speak Spanish. Sick of getting the foreigner's price? Learn Spanish. Plain and simple. It's a pretty easy to learn a couple of words and phrases here and there. Two programmes I recommend are Synergy Spanish and Fluent in 3 Months.
Be careful about meeting people you find online. I find that living abroad is safer than living at home. I've met many of my friends online through Facebook, forums, and even Craigslist. Back home you wouldn't do that. However, not everyone is safe. Meeting people online can always be dangerous. Be sure to meet in a well-lit place, preferrably during the day with other people around.
Trust your instinct. If something doesn't feel right it probably isn't. Move on and find somewhere else to go shopping.