Answer
Duplicates 1

You can only purchase the highest modification of equipment available at your rank. So if you have unlocked M1, you can't purchase M0.

Now i cant buy anything new cus im not willing to save for 3 months to get the new turret that i could buy at m0 right now -___- you srsly need to change this, cus i havent been able to try the last turret, and i wont ever be able too, i wont even be able to enter the giveaway cus i cant buy the damn thing.

If you'd have read the F.A.Q of the giveaway contest, you'll probably see this:
Q: Do I have to use Magnum to make the kills?
A: No, you can use any piece of equipment you like to complete the kills.

Can this setting be changed?
- For example, I have unlocked Ricochet M1 but I want to get the M0 so that I can complete the achievement "Collector". Similarly, tankers who want to get similar achievements (Example: Getting all M2 hulls in the garage / M1 turrets in the garage) are not able to do so.
Customer support service by UserEcho
You can only purchase the highest modification of equipment available at your rank. So if you have unlocked M1, you can't purchase M0.