Split data into linear regression
You can check the histogram of y/x. Using only values of x far from zero would be necessary, in your case its not a problem because prices are far from zero.

If in your case the three different distributions have intercept near 0, you may have useful results. You can also try to check the histogram of (y-intercept)/x.

You should find different modes in the distribution of this quotient. You could then divide the dataset according to different values of this quotient.