Sorry Steve
I missed answering your question about cost. There is/are no additional things needed with permaflex. According to the manufacturer, apply the permaflex as a primer/base coat, then, if necessary, use the LRB with the TAV thickener as necessary, to fill cracks or cold joints. Then, simply apply the final coat, let cure for approx 4 hrs. I recommend that after curing has taken place, use a mild detergent solution to wipe up any curing residue, rinse thoroughly then fill and add fish. They recommend three coats of permaflex if you're sealing cinder block. One gallon will cover about 240 sq. ft. I have found that with "new" concrete that the first coat covers about 180 sq. ft. The second coat goes on much easier of course and much less is needed. Two coats "rolled" on will give you a nice coating of about 14-15 mil in thickness. Cost is around $95/gal of permaflex and $85/gal of LRB.
Mike