library(ggplot2)

    DFF <- aggregate(eBayTrain$startprice, list(eBayTrain$productline, eBayTrain$storage, eBayTrain$color), mean)
    ggplot(DFF, aes(x=Group.1, y=c(Group.2, Group.3))) + geom_tile(aes(fill = x)) + geom_text(stat = "identity", aes(label = round(x,digits = 0)))