Okay, let me step in here to clear up some of this.
When purchasing Joker Tickets from ARMAS, you have a 1% chance per 500 JTs purchased to be granted an random legendary from the entire legendary pool. To know what all is included in that pool, head over to Anne in Social and see what she is selling. Those are the guns that you have a 1% chance to get. If you purchase a bundle of 5000 JT, you are granted 10x1% chance rolls. This is not 1x10% chance roll.
When renting legendaries from Anne, each rental costs 2500 JT for 7 days. As part of that purchase you are given 1, 5% chance to gain that specific legendary. That is for every purchase, the % chance does not stack over time. It is a 5% chance on every purchase. Currently, if you spend 50k JTs (20 purchases) on a specific legendary without getting the permanent legendary, we increase the drop rate of the next purchase to 100%. This means that if RNG is not on your side, you are spending, at most, 52.5k JTs (50k to proc the 100% chance, 2500 for the next purchase) for a permanent, tradeable legendary.
I hope this information clears up any confusion.