Are Sheldon Licenses Infinite?
You can spend 1 license to unlock a weapon that you are high enough level for, but you can spend 3 to unlock ones you do not meet the requirements.
So the question is, If I buy a bunch of "high level" guns early, will I never be able to get some earlier guns? Will you always get enough Sheldon Licenses to unlock every gun in the game, no matter the unlock order?
Seeing how you can accumulate 1 per gun by getting them to the first level of fresh its not infinite but there wont be a moment where you can't buy weapons anymore because of a lack of licences.
Since whenever you get a weapon to Freshness 1, and thats the cost to get a weapon you have the level for, then its impossible to get to a point where you cannot earn a new licence and you still have weapons to buy (since you can always get a new licence from the latest weapon you bought.)