Again, someone who has access to a CNC machine / lathe. You can't run them the way they come new. That person would have to machine them, double seal them, and test them.
Quick maths:
4x injectors @ $80 ea = $320
$739.99-$320 = $419.99
which means you're paying around $420 to have them machined, and re sealed. Not everyone will have access to a shop capable of machining it to exactly the right tolerances, and I can't imagine it would be cheap. But by all means someone take it on.
I'd rather pay the $740 to make sure they are done right and have no issues with them at all.
BTW this applies to the ones pumaspeed supplies. I have no idea if the ones Whoosh has are the same or different, but it looks like they are just the normal drop in ones. Same as Pumaspeed sells.
Edit:
Adam at Tune+ says there is no modification necessary for the ones sold by whoosh, so if those are the same injectors. Send it.