As a newcomer I perceived the situation different - a tango bubble that has taken of and lifted a decade ago. At milongas there was a clique of experienced dancers, then more or less nothing, and then me as a beginner stumbling around. This might be caused by the convenience of tango schools and their economical needs to keep the students as long as possible in their classes. But right, nowadays I prefer to attend milongas with my SO and we choose our invitation strategy after a look onto the available dancers there. BTW, i see that the price for private lessons in my area went down 25% during the last two years. But I suppose that this is caused by Argentine teachers trying to escape the inflation by earning some hard currency in Europe.