flat pen is capped at 50.

30 armor = 24% dmg reduction

So if I'm doing this correctly mages don't gain magical protection per level but instead start at 30 magical protection. Which reduces magical damage by 24%.

M.P=Magical Power

Start with Vamperic Shroud(20 M.P) and Lost Artifact(15 M.P) Then finish Shoes of Focus give (30 M.P),

Add the 3 together to get a base of 20+15+30= 65 M.P

From there we have the option of going Spear of the Magus (40 M.P and 20% pen and 15 flat pen) and cost 2150 or Doom Orb (40-140 M.P) and costs 1790.

65+30 = 95 and 20% pen and 15 flat pen or 65+140=200-15=185 for lost artifact that got consumed

95*76%=72.2 dmg(without pen calculated)

100-20%=80%

3080%=24 armor-15= 9 magical armor 95100=9,500/109=87.15

185*76%=140 dmg 100%-24%=76%

If my calculations are correct, which I've been up all night so prolly suck a$$ too tired for this atm. You can just correct any of it that is wrong and lemme know! We can see that even if enemy had 100 magical armor reducing damage done by 50% 185/2= 92.5 damage

Now then 30 magical armor if you are fighting a mage, we know unless they buy armor they'll have 30 magical protection even at level 20 most likely.

Since we bought lost artifact the cost to finish Doom Orb becomes 1190.

2150-1190 = 960g which is equal to 7.4 minion waves of last hitting the entire wave and being solo farm or if shared it'll take 14.8 waves. 7 waves = 210 seconds which = 3 minutes + 30 seconds and if you shared waves that will be 7 minutes. Now I didn't bother to calculate jungle gold splitting we'll just say the amount from jungle covers wards/pots bought for the game. I have the jungle camp gold amounts here if you want to calculate it https://docs.google.com/spreadsheets/d/13gQvZj7kBIBoVVKPVq3evzWlNkzsa3MGSRqZ_Hi_d_M/edit#gid=0.

I apologize for not making clear work or being wrong about any of it, but I did want to get my calculations out there to be corrected if need be. I do not mind failing and learning.