Accessing values of object properties in PowerShell
Once you iterate over the properties inside the foreach, they become available via $_ (current object symbol). Just like you printed the names of the properties with $_.Name, using $_.Value will print their values:
$obj.psobject.properties | % {$_.Value}
Operator precedence interprets that in the following way:
($obj.$_).Namewhich leads to nothing because you want
$obj.($_.Name)which will first evaluate the name of a property and then access it on $obj.
You don't have to iterate over all properties if you just need the value of one of them:
$obj.psobject.properties["foo"].value