I've got a maintenance client hounding me to get him some hard numbers on quite a few things...a few raised beds, massive plantings, some irrigation...all of which I'm comfortable doing. The problem is this eighty foot big-block retaining wall (he did about sixty feet of it himself three years ago then had a landscaper come in and add ten more feet to each end) that is leaking backfill like there's no tommorow. The center section seems to have been constructed properly. I can see the compacted gravel base, the vesa-grid etc...but there's no backing or vesa-grid on either end and the entire thing was backfilled with sand. The sand is steadily leaving with each rainstorm and now there's a sink-hole of collapsed sod ten feet across at either end. Access is fine on TOP of the wall, but at the base it is very tight and no chance for any type of equipment down there. To make matters worse, when the other landscape company 'finished' the ends, they buried two sweet-gum trees (sixty footers) beneath five feet of backfill! The trees have pretty much died now and will have to be removed. Here's what I'm thinking without going into too much detail...scaffolding at base to take out the end courses by hand, excavate with backhoe to make room for drainage, gravel backfill, geo-grid etc...get trees out, grind stumps...reset base course, rebuild with drainage, backfill with gravel etc...HERE'S THE QUESTION - how do I price this? Per foot on a normal install, but this is my first big deconstruction and (for me) there are alot of unknowns, that leaves t&m...but at what rate? I solo-operate maintenance and run a two man crew for installs. Any help or directions to useful threads would be appreciated.