And you're missing my point entirely, to build a trainer for a valkyrie, you would have to build a whole new bird that transforms. So this new dedicated trainer would be just as expensive as building a valkyrie. Only now, you have to dedicate new factories, train your mechanics to work on two birds, have duplicate but unique support equipment, etc.
what's more expensive?
And also, who said that the 1d didn't have it's fundamental capabilities intact?
does it fly? yes.
does it transform? yes.
Does it have hands to pick things up with? yes
Does a gunpod have a hand grip to be picked up with? yes.
So what's your issue?