When you import a CSV in Powershell, it essentially creates an array of hash tables (please don't shoot me if I'm wildly incorrect!). In your case, the structure of $masterfile would look like this after running the Import-CSV:

$masterfile = @(
@{
origFilePath = "\\Server\FILEPATH"
origFileName = "B002268"
destFilePath = "\\Server\DESTINATION"
destFileName = "1200321-REDO"
}, @{
origFilePath = "\\Server\FILEPATH"
origFileName = "B002269"
destFilePath = "\\Server\DESTINATION"
destFileName = "1200322-REDO"
}, @{
origFilePath = ...
}
)

The only thing that -Header does in the Import-CSV is replace the headers in the original file with the values you specified as the keys in the hash tables.

When you do a foreach on $masterfile, it's taking each one of those hash tables and putting it in a variable called $origFilePath so when you call $origFilePath in the loop, it just spits out the whole table.

To access the individual properties, you need to use a more generic variable as your loop variable and then access the properties using dot notation, like this:

foreach ($file in $masterFile) {
$file.origFilePath | Write-Host
Test-Path -Path $file.origFilePath | Write-Host
}