Right now rosh is a really significant objective. Makes a difference between being able to high ground or comeback.
What if you could buy a 1000 ( starting cost) to 1500 ( max cost) gold item ( cost increases depending on the game timer) and block the next roshan from spawn.
You won't be able to purchase the item at start of game. You would only be able to purchase it after the first rosh has been killed. The item lasts for 11 min in blocking the rosh spawn, after expiration the next rosh will spawn.
It can be trade off, having buyback vs preventing enemy from rosh and potential high ground and end.
There are obviously ways to grief your own team with this if you have a hero that relies on aegis often ( ursa, huskar etc.) . But you can grief your team with any item in the game, and some cost less than 100 gold.
The most significant case of this would be when rosh is on potential refresher orb drop. If enemy has a hero like faceless void, enigma, earth shaker etc. Preventing them from potentially having it makes a difference of high ground success and failure.
Source: https://www.reddit.com/r/DotA2/comments/x0x3n0/new_game_mechanic_idea_block_roshan_pit_from_rosh/
