Tree Upgrades

The Evolution Tree (also referred to as "Tree Upgrades" or "Skill Tree") is a major feature exclusive to to Scrap Clicker 2 and is unlocked at x40 Stars. At first, only 5 upgrades are unlocked and additional upgrades are unlocked every x5 Stars until x130 Stars and then every x10 and later x25 Stars or more. Upgrades are purchased with Golden Scrap, Star Fragments, Magnets, Steel Beams, Wrenches and Mastery tokens.

x45 Stars

 * The Scrap boost upgrade costed 250 Steel Beams until 9.5, where it was changed to 200.

x225 Stars
Note that the last upgrade (About Merge levels) was not added for a long time: Until 7.1.

x2000 Stars
Note: Upgrades which will come soon are indicated with the symbol to the right

Trivia

 * The cost of all upgrades available through x1000 Stars is 94,150 Star Fragments, 5,554,000 Magnets, 62,18B Golden Scrap, 9,775 Steel Beams and 710,354,825 Wrenches.
 * The Million Merge Boost upgrade used to say "Get a x1.05 Magnet Boost every 1 Million Merges" and also have that effect before version 8.4.