Dota 2 v7.11 overhauled the AoE gold and buyback cost. If you don’t like math and formulas, check out these charts and summaries of the changes.
RedSpah worked on some graphs to explain accurately the differences between the old and the new system, and kindly gave us permission to share his data.
Buyback cost - 7.10 to 7.11
Buyback cost changed from 100 + ( Level * Level * 1.5) + (Time * 0.25) to 100 + Networth / 13
Buyback no longer reduces gold earned after respawning
The graph below utilizes data from a pro game as a real-life example of the adjustments: game one of Virtus.pro versus Team Liquid during the semifinals of The Bucharest Major.
Dotabuff link of the match.
The cost of the buyback for cores is increased.
Unless really poor, generally you will pay more for a buyback.
Supports will always pay less than before, particularly in pro games as they usually devote more resources to the team.
AoE Assist gold - 7.10 to 7.11
AoE gold for the losing team no longer scales with the overall team networth difference, just the individual networth of the dying hero. Previously, a core on your team doing really well meant that a support on your team dying gave an increasing amount of gold to the enemy.
The following graphs show how much gold each participant to a successful gank will earn in a solo, 3-man, and 5-man gank if they are at least 20% behind on networth, which equals to a 14k gold lead for the winning team at minute 30.
Now, there is less AoE gold available for comebacks, and slaying a support brings only a small amount of gold in your hands. Instead, solo ganks reward more gold, especially when killing a core hero.