Why do tank items have horrible cost efficiency?
Look at this:
for 2900
425 hp = 1133
60 armor = 1200
Total = 2333 = 80% cost efficient
for 2900
425 hp = 1133
60 armor = 1200
Total = 2333 = 80% cost efficient
for 2900
350 hp = 933
60 armor = 1200
Total = 2133 = 74% cost efficient (that's just pathetic)
for 2800
300 hp = 800
55 mr = 990
100% hp regen = 300
10% cdr = 300
Total = 2390 = 85%
for 2800
300 hp = 800
65 mr = 1170
100% hp regen = 300
10% cdr = 300
Total = 2570 = 92%
for 2100
30 armor = 600
60 mr = 1080
Total = 1680 = 80%
for 2700
400 mana= 560
90 armor = 1800
20% cdr = 600
Total = 2960 = 110%, but mana is usually not useful for a tank, so in actuality, total = 2400 = 89%
for 2625,
400 hp = 1067,
15% hp = 300 hp = 800, lets say you have 2000 bonus hp
Total = 1867 = 71% (seriously wtf)
for 2800
450 hp = 1200
55 mr = 990
100% hp regen = 300
10% cdr = 300
Total = 2790 = 100%
for 2350
100 armor = 2000
Total = 2000 = 85%
Seriously, armor items for tanks are so cost inefficient but they need them to survive adcs and ad assassins. What makes it worse is items like 
devalue tank items even more making them even more cost inefficient. If the enemy adc has a last whisper, becomes 59% gold efficient against him. Not to mention tanks don't have much to mitigate burst ad damage, so if a zed gets fed and gets some %shred, well lets just say you won't last long. Seriously, I am better off stacking 
and 
to try to tank instead of investing in horribly inefficient items. I suggest we buff the base stats on them so that tanks can actually feel good about buying them.
so god damn cheap for how good it is
for 3500
80 ad = 2800
15% vamp = 562 (comes from 10% = 375)
10% cdr = 300
Total = 3662 = 105%
for 3100
55 ad = 1925
35 mr = 630
15 lethality = 337
Total = 2892 = 93%
for 2625
60 ad = 2100
10% cdr = 300
Total = 2400 = 91%
for 3400
70 ad = 2450
20% crit = 800
10% cdr = 300
Total = 3550 = 104%
for 3100
700 hp = 1867
30 ad = 1080
Total = 2947 = 95%
for 300
300 hp = 800
400 mana = 560
80 ap = 1740
Total = 3100 = 103%
for 3400
40 ad = 1400
80 ap = 1740
15% vamp = 562
Total = 3702 = 109%
for 2500
300 hp = 800
60 ap = 1305
10% cdr = 300
Total = 2405 = 96%
for 3250
50 ad = 1750
45 mr = 810
10% cdr = 300
Total = 2860 = 88%
Lifegrip activated:
20 ad = 700
10% life steal = 375
Total with lifegrip = 3935 = 121%
for 3600
65 ad = 2340
35 mr = 630
10% life steal = 375
Total = 3345 = 93%
for 2900
100 ap = 2175
400 mana = 560
20% cdr = 600
Total = 3335 = 115% (holy shit)
for 2600
45% as = 1125
30% crit = 1200
5% speed = 195
Total = 2520 = 93%
for 3700
80 ad = 2800
20% life steal = 750
Total = 3550 = 96%
for 3733
250 hp = 667
250 mana = 350
25 ad = 900
40% as = 1000
20% cdr = 600
5% speed = 195
Total = 3713 = 99%
for 2900
60 ad = 2100
10% cdr = 300
15 lethality = 337
Total = 2737 = 94%
without sacrificing anything.
etc.
