N18 Van saar ash waste starting gang / arachni-rig

Hello there !
I'm building up an ash waste van saar team and I was wondering about the ash waste arachni-rig.
can we buy it with the 400 cred that must be allocated to vehicules, crew or mounted equipment ?
As it's not a vehicule nor a mounted equipment but a brute ? Then why label it ash waste arachni-rig ?

Thanks for your enlightment.