The average Thai probably makes 12,000-20,000 (US$375-$625) baht per month, depending on qualifications. Some people get paid even less. Farmers, fisherpersons (politically correct fishermen? haha), laborers, etc. make even less than that.
But yeah, the prices on internet are still pretty steep, not as bad as they used to be, but still too much. And you don't really get what you paid for. Internet here is crappy and unreliable. Those speeds are only guaranteed within Thailand and not for international connections, and even locally they only guarantee you 80% speed. So as long as your connection to the ISP's servers reaches 80%, it doesn't matter what your connection to websites located outside Thailand is.
There are also only 4 international connections in Thailand, and if one of those goes down you might as well forget about accessing anything that's not hosted in Thailand (which happens about once a month).
-=EDIT=-
One of the links Aegis made actually brought up a good point.
The figures I've stated are only for Bangkok. There are people in rural areas that make even less. To be honest, comparing Bangkok to rural areas is like comparing apples to oranges... two completely different things.
But for the point of my original post, statistics for Bangkok and other hubs (Chiang Mai, Phuket, Pattaya) are the only really important ones. A lot of rural areas don't have access to computers or high speed internet or even telephone lines for that matter... but they all have cell phones, believe it or not.
