These are all the French artillery (Self propelled guns) in the game (not including premium SPG's):
Tier 2: Renault FT 75 BS - XP: 145 - Credits: 3,700
Tier 3: Lorraine 39L AM - XP: 1450 - Credits: 51,000
Tier 4: AMX 105 AM mle. 47 - XP: 3100 - Credits: 124,000
tier 5: AMX 13 105 AM mle. 50 - XP: 15220 - Credits: 410,000
Tier 6: AMX 13 F3 AM - XP: 31900 - Credits: 935,000
Tier 7: Lorraine 155 mle. 50 - XP: 60750 - Credits: 1,420,000
Tier 8: Lorraine 155 mle. 51 - XP: 92100 - Credits: 2,550,000
Tier 9: Bat.-Châtillon 155 55 - XP: 182000 - Credits: 3,500,000
Tier 10: Bat.-Châtillon 155 58 - XP: 277000 - Credits: 6,100,000
Please note* i do not take in to account the price and XP cost of modules (Gun's, engine's, tracks etc) on each tank, you will have to research some of them in order to proceed to the next tank.
Obviously you need to have 5 of those in your garage at the same time, the most common rout to get those 5 would be to start from tier 2 with the Renault FT 75 BS and just keep grinding until you have all the SPG's from tier 2-6.
But if you happen to have the French light tank AMX 12t you can grind the Tier 6: AMX 13 F3 AM with that tank, but i still recommend doing the rest of the low tiers because they are way cheaper in both XP and credits to get than the high tier artillery.
Make sure you have enough garage slots. it will require you to have 5 empty slots so you can buy have them in the garage at the same time
if you don't have enough garage slots you have to options:
1. Sell some of your tanks
2. buy new garage slots with gold (buying gold cost real money)
Note* you can get a few hundred gold by completing the tutorials.
But everyone should have enough garage slots if they sell a few tank so you don't have to use real money, therefore i recommend you sell the tanks instead, remember you can buy them back at any time.
you can get:
while grinding the french artillery.
any questions or suggestions? ask below.