Thanks, Bryan!
So the interaction effect is not of concern as long as I do not aim at comparing brands on a specific price level?
I thought I could only interpret the main effect seperately in a main effects plus interaction effects model, if my design is orthogonal, but it isn't since I used balanced overlap as task generation method and I have less products shown in a choice task than the number of levels of the attribute with the largest number of levels. Or can I do so because of using effects-coding?
I am just wondering since Hensher et al (Applied Choice Analysis) caution interpreting the main effects alone if interactions are involved in the model.