Duplicate file finder?

Add-Type -Language CSharp @"
public class item{
    public string Fullname;
    public string Hash;
}
"@;

$ITEMS = New-Object System.Collections.ArrayList
$DUPES = New-Object System.Collections.ArrayList
#$BASEDIR = "D:\Music\"
$BASEDIR = "C:\users\justin\documents"

$START = [DateTime]::Now

echo "Building file list..."
Get-ChildItem -Path $BASEDIR -Recurse | Where-Object { !$_.PSIsContainer } | Select-Object FullName | 
% {
    $temp = new-object item
    $temp.FullName = $_.FullName.toString()
    $temp.Hash = (Get-fileHash($_.fullName)).Hash
    $ITEMS.Add($temp) > $null
  }
echo " " > dupeshash_music.txt
$count = $ITEMS.count
$inc = [int]($count/80)
$step=0
echo "Looking for duplicates in $($count) files..."
Write-Host "|=" -NoNewline
foreach ($item in $ITEMS)
{
    if($step -eq $inc)
    {
        Write-Host "=" -NoNewline
        $step = 0 
    }
    $step+=1
   
    if($DUPES.Contains($item.FullName))
    {
        continue
    }
    else
    {
        for ($i=0;$i -lt $ITEMS.Count; $i++)
        {
            if( ($item.hash -eq $ITEMS[$i].hash) -and ($item.FullName -ne $ITEMS[$i].Fullname))
            {
                $DUPES.Add(($ITEMS[$i]).FullName) > $null
                echo "Original: $($item.FullName)`tDupe: $($ITEMS[$i].FullName)" >> dupeshash_music.txt
            }
        }
    }

}
Write-Host "|"
#$DUPES | % { "$_ is a duplicate file" }
$STOP = [DateTime]::Now
$E = ($STOP - $START)
echo "Found $($DUPES.count) dupes in $E"

PS C:\Users\Justin\Desktop\dedupe> C:\Users\Justin\Desktop\dedupe\dedupe2.ps1
Building file list...
Looking for duplicates in 1063 files...
|==================================================================================|
Found 33 dupes in 00:00:11.5479961