To answer your question, the 1:1 ratio means that if you want a $12k Birkin, that it usually will not be offered until you buy $12k of other items such as jewelry, clothing, other handbags, etc.
Your history matters. One time I visited A store in NY and has a great conversation with an SA. This was before I knew about the whole relationship thing. So I looked at some bags for the wife and also mentioned that her birthday was coming up and that she had always wanted a Birkin. This store gets great inventory so the SA said he could have a Birkin for me by the following week. He then looked up my name and I only had a few small things like ties and a wallet. He comes over and says “There is a problem. Our system isn’t showing that you buy anything from Hermes”. At the time, we bought our Hermes items from a non-Hermes store in Connecticut that carried Hermes items so all of our history didn’t show up in Hermes’ systems. The offer of a Birkin for her birthday immediately disappeared and it soured me to the store and SA all together.
Fast forward a couple years and Hermes opened a boutique in Connecticut. We walked in and bought an Evelyne for the wife. Wife was carrying her Lindy bag and the SA says “That bag isn’t showing up in our system. Did you happen to buy it at the store down the street?” The answer was yes and she says to me “Thank you and I hope that your wife loves her Evelyne bag. If you need ANYTHING in the future, please let me know. Here is my card”
She helped us get that Birkin for the wife’s birthday and has helped us with many bags since. A few days ago, we walked back into the NYC store that I had sworn off, and a lovely SA was assigned to us. She looked up my name because we asked for a Constance bag and she told me essentially every quota bag that they had in stock in case we wanted one.
Long store short, history matters.