The answer is $5.25 for 1 1/2
The reasonings for this is
Step 1. Find out that we at least would have to pay $3.50.
Step 2. Find an equation to represent how much the half costs.
Step 3. Solve said equation.
Step 4. Add final products.
Visual of step 2, 3, and 4.
Step 2 visual. $3.50 ➗ 2 = ?
Step 3 visual. $3.50 ➗ 2 = $1.75
Step 4 visual. $3.50 ➕ $1.75 = $5.25
( sorry this is late )