Just looking for an average of the cost for installing a 100-150 amp subpanel in my basement from the garage. There are plenty of empty panels on the main service panel and the run to the sub panel will be between 70-80 ft. I live in Iowa and will have a certified electrician do the work. Just looking for what a reasonable rate is for a job like that. Thanks in advance

Your most accurate answer would come from calling for 3 estimates from licenced electricians in your area. Labor cost vary greatly since we don't know if you are in downtown DuBuque or in the middle of a corn field.

Just know that you will likely not get a 150A sub-panel.
Most residential panels are rated for 100 or 125 amp maximum individual branch circuits.