Sum of Range based on reference cell.

Hi All, appreciate all help provided, Simply yet challenging for me.

I need to add the cell values in a range which is defined by A1 value.

A1 A2 A3 A4 A5 A6 A7 A8

3 * $1 $2 $3 $4 $5 $6

So A1= number of days away
A3= Day 1 price
A4= Day 2 price
A5= Day 3 Price.

Simply put, I need to add the next 3 cell to the right of the *. I.E I want the answer to be $6 for 3 days. and for 5 days $21. Simple yet confusing me. I cant work out which formula to use and how to get A1 as a reference for the range length.

Thankyou .