Started wtih 700$ and traded & added to my collection as time has gone on.
If you play the game, could be a good investment to buy new collection pinks & reds ( Collection skins not Cases)
Collections mainly only drop during operations, If that collection does not come back, those skins will never be dropped again, therefor making the Pinks a high demands due to replenishing quantity as people trade up to the reds.
Not a financial advisor but i had 800$ off the Blue Phosphor and Target Acquired.