well looking at the decay set as a whole u can get a good-perfect set wtiha FF rune for about 110FSP max. the rune is now only selling for 95-100 fsp perfect FF and it does help alot i mean it lasts from lvl 90 to lvl 168 when a cheap 75K rune u can buy from a shop beats it lol
ill be using my rune till then and with proper buffs and a good setup and good guild u can 1 hit alot from 140-160.
The point is, however, that why to pay additional 80 fsps for just additional 50 damage points? Is it really impossible to get these additional 50 damage points from other combinations of items ? If you look at other items for gold that follow you all the way, you found out that those are worse by just several stats points than the "popular" set items, but their cost is so low that you can even drop and destroy them later... People are levelling up fast even without these popular items...