The original Korblox Deathspeaker item in Roblox is commonly listed at 17,000 Robux in the sources I found, which is why people often call it very expensive. A lot of “Core Blocks”/Korblox alternatives seen online are cheaper lookalikes, with examples ranging from 50 to 400 Robux depending on the method or bundle.

What that means

  • Legit Korblox Deathspeaker: about 17,000 Robux.
  • Cheaper fake/lookalike versions: often 65, 75–85, 100, 125, 175, or 400 Robux depending on the item or bundle used.
  • Some videos also mention the item as costing roughly $200+ in real money terms.

Quick note

If you meant a specific Roblox item named “Core Blocks,” the price can vary by the exact catalog item, because several videos and posts use that name loosely for Korblox-style avatar tricks.

TL;DR: the real Korblox-style item is about 17,000 Robux , while cheaper “core blocks” lookalikes can be anywhere from 50 to 400 Robux.