Please review the documents in the Technical Papers library showing the strong bias ACA has for getting the importance of Price too low. ACA alone (without special adjustments and calibration) often will overstate Willingness to Pay by a factor of 2x to 4x.
Within our SSI Web system, there are many ways to ask additional questions outside of the ACA portion of the survey.
Just, please, proceed with caution in this area, as it is fraught with peril.
Adaptive CBC is considered a much stronger tool for estimating more realistic price sensitivity for conjoint studies that involve about 5 attributes or more.