Search For The Needle Drone Guide
What the Drone actually does
The in-game description shown in a complete playthrough says the Drone flies to the haystack, fills up, carries the load to the cow and comes straight back. That makes it a background worker, not a replacement for your main tool.
Cost
The focused fast-route video shows a 40 Gem Drone purchase. Because class spins also cost 40 Gems, this is a real trade-off: one faster run versus one permanent class roll.
Best upgrade pattern
Upgrade the Drone enough that it is no longer crawling through tiny loads. The focused guide raises its collection stats several times, then stops and returns to saving for the Vacuum. That is the right idea: get meaningful passive value, then move on.
Can you have multiple Drones?
Be careful with this claim. One long video briefly speculates about buying several Drones, then later discovers the standard purchase is limited in that run. A class preview for Drone Specialist mentions extra-drone behavior/chance. Do not assume every player can simply buy a permanent fleet from the normal tool station.
Is the Drone worth 40 Gems?
For a first clear, yes if you have enough Gems after considering classes. It earns while you dig, which means its value scales with how long the run lasts — and Chapter 1 can be a long run without paid shortcuts.