Full Ti??? I'm not aware that Muzzy ever made the header and collector in Ti. (Pretty sure I even asked the rep at Muzzy about that before buying.) They did make the cover of the muffler in Ti (I have one on my stainless Muzzy 4-2-1 system). Very noticeable HP boost (PowerCommander suggested) and one of the best sounding systems available (I run their "Quiet Core" baffle in the can, but have their louder regular core baffle new in a box somewhere in the garage).
Before he sold his '05, CAJW used to covet my system and spent some time trying to find one (Muzzy quit making them for the FJR) with stainless or Ti can cover. Rare to find circa 2012 - 2013, and really spendy, IIRC. He might remember the price range better than I do and may chime in here, but it seems that for NOS or nearly mint Muzzy 4-2-1 systems, people were asking insane prices just short of $1K. I don't need one, but would gladly match that $100 offer you already got. ;-p
Another issue for the 4-2-1 system on Gens 1 & 2 (the only FJR gens when Muzzy was making these systems for the FJR) was scraping the collector on hard mid corner compression with the undersprung OEM suspension of the FJR. I cured that for good with a ride-in at GP Suspension, but there were several complaints from full system owners who had not made that suspension commitment.