With my Javazon I will have to get insanely lucky with runes to make an infiinity. I mean, you only need two Bers. Three with the realization that if you find one you might want to make Enigma first. That should be easy. 
Yeah...LIs are going to be the Bane of my existence with the Javazon.
How long before some SP players are going to be duping runes? *sigh*
This post needs a bit of a reality check. Your build will be hell viable without any high runes at all. LIs will be a pain, but you also have physical damage options. And thats how D2 was built. I know you've played a whole lot of other games I haven't so I'm not sure how they do them, but you have a viable build that will slay large amounts of enemies quickly. For LIs you have options of secondary attacks, or maybe you'll park them. Maybe you'll save and quit and see if the boss rolls with something more favourable?
In the last couple of patches, rune drop rates have been tweaked MULTIPLE TIMES. In 1.09 I never saw an UM or above and not from a lack of looking. In 1.14 I've had a BER drop from pindles pack. I've seen lots of other runes, LO, OHM, VEX, SUR etc. Some just from playing normally, some from targetting things such as the Travincal pack, or I tried opening superchests in Lower Kurast.
I eventually made an enigma many years back without duping, and it is a thing of beauty .. but its not required at all. I had a look, I have a skullders on mine, other options might be Fortitude (not too expensive) El + Sol + Dol + Lo
Body Armor
20% Chance To Cast Level 15 Chilling Armor when Struck
+25% Faster Cast Rate
+300% Enhanced Damage
+200% Enhanced Defense
+15 Defense
+X To Life (Based on Character Level)*
Replenish Life +7
+5% To Maximum Lightning Resist
All Resistances +25-30 (varies)
Damage Reduced By 7
12% Damage Taken Goes To Mana
+1 To Light Radius
I'm yet to make infinity, its on my wishlist after Beast, and it will help out I'm sure.
I know some people have duped runes in the past, but you don't have to. It comes down to matching your goals to your willingness to play. Anecdotally, those who do dupe have a big buzz of getting to the destination, and then they normally burn out quickly.
Don't forget, we don't know HOW these will be able to spawn, but Anni and Torch will be available in SP now, check out these stats to help you. All that res, attributes, skills will help move characters to another level, or give more options in other gear, you won't need to worry about resistance in gear/charms as much.
Annihilus*
Small Charm
Required Level: 70
+1 To All Skills
+10-20 To All Attributes (varies)
All Resistances +10-20 (varies)
+5-10% To Experience Gained (varies)
(Only Spawns In Patch 1.10 or later)
Hellfire Torch*
Large Charm
Required Level: 75
5% Chance To Cast level 10 Firestorm* On Striking
+3 to Random Character Class Skills (varies)
+10-20 To All Attributes (varies)
All Resistances +10-20 (varies)
+8 To Light Radius
Level 30 Hydra (10 charges)
(Only Spawns In Patch 1.13 or later)
So .. bit of a reality check plus some optimism. You are going to be having a LOT more fun than frustration.
