being the prudent one in my family, I did a bit of cost analysis.
Complete 9mm upper for a G19:  $379 at "something" tactical, one off of Wolf Barrels
Lower parts kit from Brownell's:   $49
Polymer 80:                                $160
$580
New Glock:  $509 at Budsgunshop.
Makes a world of difference IF your hand doesn't fit the OEM grips tho.  I might still build one, but mostly for the honor of having no serial number.  Everyone should have one that gummint don't know about.
Oh and btw... I am also a two 

 owner. G19 gen2 and a G21SF gen3.  Like them both. They would be my first choice bugout firearms. 
dafadda