fwiw - I figure add $1.90/lb (round it out to $2 to make it EZ) or so to get a cost comparison for "peeled" tri-tip.
Also, there are some good youtube vids for trimming tri-tips. After you have done a few, it goes rather rapidly.
TT pricing is getting real good of late. Was at Costco today & choice peeled TT was less than $5/lb.