Well, some down, but not yet there. No more compile errors on the visibility, thanks guys! Its got:
 val:runtime.htl? > 0 
 And this makes sense to me.
 The "second part" is the second example code block from Handling Units with Resource Pools.
 The example is this:
 ~ Get the number of unspent points
 var unspent as number
 unspent = unit.stat[PtsMax] - unit.stat[PtsUsed]
 ~ Determine if more points were used than allowed
 var is_exceed as number
 if (unspent >= 0) then
 is_exceed = 0
 else
 is_exceed = 1
 endif
 ~ Set the option name to the unspent points remaining and use red if exceeded
 name = "Item Points Left: " & unspent
 if (is_exceed > 0) then
 name = "{text ff0000}" & name & "{text 010101}"
 endif
 
 I'm using:
 ~ Work out how many points of items we're allowed
 var result as number
 result = unit.stat[htl] - val:runtime.htl?
 ~ Check to see if I'm over the limit
 var is_exceed as number
 if (result >= 0) then
 is_exceed = 0
 else
 is_exceed = 1
 endif
 ~ Set the option name to the unspent points remaining and use red if exceeded
 name = "HT Points Left: " & result
 if (is_exceed > 0) then
 name = "{text ff0000}" & name & "{text 010101}"
 else
 name = "{text 80ff80}" & name & "{text 010101}"
 endif
 Its defining that val:runtime.htl? sucker; it gives me a compile error every time.
 I've read and read read all the doc's mentioned, tried numerous combinations of syntax expression: result = (unit.stat[htl] - val:runtime.htl?), etc
 And still compile errors.
 As long as I cut out "side two" of the expression:
 side one side two 
 result = unit.stat[htl] - val:runtime.htl?
 It will compile, but of course I never calculate how much of htl got used, so its rather pointless. But, it does let me know thats got to be where I'm still making the error.
 So, why is it working in visibility, but not in cost? I've been beating my head into this one for too many hours now to give up, but I'm starting to wonder if a item count was really worth it 
 .