I'm in a flood zone and the county forced me to build a 4 foot above grade wall/slab.   On top of this 8 foot high ICF walls will be built.   That makes a total of 12 ft from the outside and 8 ft from the inside.   Somebody said I need a concrete boom for that height.   Do I really?   Can't I just get a pumper with a long hose and fill the ICF's in from the inside where the height is 8 feet?

No problem using a line pump but beware of kick.

A line pump will usually cost less but will require more labor.  Some pump companies rates will include labor for two people, that is, the pump operator and the hose man.  Boom pump companies usually furnish the operator and not the hose man.  Check on rates and be sure to include all of the miscellaneous charges that go along with pumping concrete.

The extra you pay for the boom will be well appreciated for by your back.

12' high walls, 3 lifts

Picture dragging a hose on top of the wall, fighting with it to move it all the way around, when done, start again and then again

Let's just say I call it a few hundred extra of well spent money.

We run into it in the city infill lots and overhead wires regularly, we price the job considering all factors, one being pump access

Good advice - but don't forget the kick as it's also more dangerous to use a line pump than the typical pump truck. Regards.

Boom pump all the way, line pump is triple the work.

What are you really saving?

A line pump may usually cost more (because it is at least triple the work) -- but you use one when you must - e.g. Power lines or location etc.