There are two events running side by side. The Expo and the Trade Fair. Some of the events at the Expo are not open to the public. The Trade Fair is open to all.

New update:
Went to the Expo today to check it out. No line at all to get tickets. Took 1 minute. Cost 30 yuan. No, foreigners do not get in for free. Thought it only lasted 4 days. Actually it lasts 5, through Monday.

Was that the Expo, the Trade Fair or both?

@Dazzer
It's both. They're both included in the single ticket price of 30 kuai.

I'm back from the Expo/Trade Fair and want to post my reactions.

I attended a previous version of this 3 years ago. Then it was called the "Southeast Asian Import/Export Trade Fair". I thought it was a pretty interesting even at the time. Hundreds of booths with vendors from countries all over Southeast Asia. In fact, even then, it was more than just Southeast Asia. India, Sri Lanka, Bangladesh, Pakistan, and the Maldives were all there, so in reality it could have been called the "South Asia Import/Export Trade Fair". My favorite part of that fair was the booths from all the prefecture and county governments in Yunnan, promoting investment opportunities and touting infrastructure and development projects in their respective areas. I collected a lot of interesting brochures that day.

This event, which has been built up through months of advertising, promotion, billboards, and text message reminders from the government, was being billed as something different. Not only was it the "21st Annual Import/Export Trade Show", it was also the "First Annual South Asia Expo". Obviously, I expected it to be something different and bigger.

What I saw was essentially the exact same thing I saw 3 years ago, but without the interesting regional development exhibits. The only difference was there were a few more countries in the trade fair (including ones from Africa and Central Asia), and there were way more people in attendance. In fact the event was so crowded that it was really unbearable to be there, almost impossible to even move through the crowds.

I figured the hoards of attendees were there for the same reason I was...they were fooled by the marketing which promises an Expo. All it was was another trade show. Where was the Expo? I'm told some of the Expo activities took place behind closed doors. That sounds more to me like a conference, not an Expo. The word Expo comes from the World Exposition, like the one in New York 1964, or Shanghai 2010. Part of the purpose of an Expo is to promote business and trade, yes, but part of it is also to promote culture and entertainment. I attended the Shanghai Expo and every participating country had a pavilion where you could meet people from that country and learn something about that country's culture, history, geography, and economy. There was nothing like that at this event. This event was purely a trade show, nothing else.

I feel like Kunming really dropped the ball on this and over-hyped this as something much more than it really was.

I LOVE THE NAN BO( South Asia Expo)!! WATER PRESSURE 24/7 FOR THE PAST WEEK!

Sorry, had to get that out!

@Yuantongsi

Is that why water pressure has been so good? Okay, I'm in agreement with you then!

Expos will usually have a conference, and private dinners on the side. You can pre-register as a delegate for the conference. You can buy tickets for the dinners, but you need to be an exhibitor or delegate usually.