If you need support from IBM because something is broken and needs fixed, then file a PMR.
If you need help working with BigFix in general, then your best bet is posting to the forums here.
If you want paid consulting / content development / and other paid services around BigFix, then you can try IBM Professional Services or IBM AVP or IBM Global Services in addition to the third party you are already in contact with.
$175/hr does not sound overly expensive for BigFix consulting. I think IBM charges more in some cases, but maybe less in others. The range for BigFix work seems to be from $100 to $500 per hour.