Where should I sell exploration data for the most benefit?

Solution 1:

Since nobody else is posting information of value, I'll summarize what I've dug up from the Elite Dangerous Wiki.

Engineers

Not all Engineers accept exploration data for advancement. Below is a list of those that do, and where to sell. You'll have to unlock the Engineers to G1, by performing their individual task, before you can sell exploration data to unlock higher tiers. More information about unlocking the Engineers can be found on the Elite Dangerous Wiki.

All bases listed in this section are Planetary locations - you'll need Horizons to access them, and they accept any ship size up to and including Large.

• Felicity Farseer at Farseer Inc. (Deciat 6 A)
• Elvira Martuuk at Long Sight Base (Khun 5)
• Selene Jean at Prospector's Rest (Kuk B 3)
• Professor Palin at Palin Research Centre (Maia A 3 A)
• Lori Jameson at Jameson Base (Shinrarta Dezhra A 1)*
• Ram Tah at Phoenix Base (Meene AB 5 D)
• The Sarge at The Beach (Beta-3 Tucani 2 B A)

* Shinrarta Dezhra requires a permit from the Pilots Federation, which is obtained once you reach Elite rank in any category.

System Permits

Many systems require a Permit before you can jump to them. Some Permits require you to gain ranks with certain Superpowers, while others are granted upon completing an in-game achievement. Then there's a large number of Permits which are currently a mystery to us - nobody knows how to get them.

Besides all of the above, there remain a number of permits which can be obtained by reaching Allied status with a specific Minor Faction. There's several ways to achieve this, and one of them is to sell a load of exploration data to a station controlled by the Minor Faction in question.

Below is a list of permits that can be obtained through reaching Ally status with a Minor Faction. You will need to seek out a System and Station controlled by the Minor Faction yourself, as game mechanics permit ownership of these to change frequently. EDDB is a good resource for this.

• Isinor
  • Faction: Chapter of Isinor
• Terra Mater
  • Faction: Brotherhood of Terra Mater
  • Note: Rare Goods (Terra Mater Blood Bores) available.
• Jotun
  • Faction: Dukes of Jotun
  • Note: Rare Goods (Jotun Mookah) available.
• Sirus
  • Faction: Sirius Corporation
  • Note: Home to Engineer, Marco Qwent.
• van Maanen's Star
  • Faction: Sublime Order of Van Maanen's Star
• Peregrina
  • Faction: Peregrina Aristocrats
• Luyten 347-14
  • Faction: Luyten 347-14 Prison Colony
• Hodack
  • Faction: Hodack Prison Colony
• Crom
  • Faction: Crom Silver Boys
  • Note: Rare Goods (Crom Silver Fesh) available.
• Pi Mensae
  • Faction: Pi Mensae Brotherhood
• LTT 198
  • Faction: LTT 198 Order
• Nastrond
  • Faction: Defence Party of Nastrond
• Tiliala**
  • Factions: Conservatives of Tiliala, The Black Fleet

**Note: It is possible, though extremely rare, that game mechanics may force Permit control to change hands between Minor Factions. Tiliala is one such case. More details of how this happened are on Galnet News. When in doubt about Permit control, check the Elite Dangerous Wiki.

Solution 2:

Just to add something if you find this helpful.

I just tried this with Selene Jean.

Sell approximately 1.5 Mil worth of exploration data can get you from G1 repututation to G3, just enough to unlock their succeeding engineers. Sell 3.5 Mil to G4. You need a massive amount of 13 Mil in order to reach G5. But it is a good place to sell to considering you can save your material by raising reputation before you craft anything since it will reduce the number of rolls required.