TFM as detailed on pages 70 & 71 #7 says REPLACEMENT TREE COST is the cost of a replacement size tree and can be wholesale, retail or installed.

# 9 says INSTALLED TREE COST equals (REPLACEMENT TREE COST plus INSTALLATION COST). If installed RTC (as allowed in #7 is used in this equation IC will be double counted.

So, INSTALLED TREE COST as calculated in #9 and used in the calculation of UNIT TREE COST in #10 equals installed REPLACEMENT TREE COST as described in #7

So, to avoid both confusion and inadvertent double counting and to be consistent with #'s 9 and 10, REPLACEMENT TREE COST as described in #7 should be wholesale or retail only. Installed should not be an option in #7.