private void getMinMaxBtn_Click(object sender, EventArgs e)
{
var minMaxItems = PriceCaluclator.CalculateMinMax();
var minList = PriceCaluclator.GetMin(minMaxItems);
var maxList = PriceCaluclator.GetMax(minMaxItems);
minlbl.Text = minList;
maxlbl.Text = maxList;
}