So rough estimates....

7 Sacreds, 30M silver, 1000 gems.  

Shards are always the most crucial but if youre doing UNM everyday you get plenty in-between fusions to do them all if you choose.

Since you are late game already, you can easily complete fusions with the resources the game provides.  

For many players, it does require a shift in play-style:  Shards, Soulstones & Gems are resources that must be saved and managed in order to facilitate the compeltion of Fusions, Titan Events & Path Events.

If you can't embrace that Deferal of Gratification, you won't be able to complete fusions and other events as a F2P player. 

Hydrid Fusions are the toughest; Traditional are the mid-ground; Frag collectors are the easiest. The fusion that starts next week is a frag collector, so that is the best time to get your feet wet....assuming you have some Sacreds in the bank.