I voted for finding a dupe, but reading you really love this shade and pretty much just wear the 1 shade, I would buy as many as I can reasonably use in the time that they will still be fresh. Lipsticks can last a really long time, but I do have some old ones that are not fresh, so they are kind of hard, smell like crayons, and the color is not the same, it oxidized more orange than what the original shade was. For now they are still usable to me if I want an orangish shade and I can also use them for blending with other colors, but many people would probably not want to use these lipsticks, so I would keep in mind lipstick doesn't necessarily have an unlimited shelf life.
So in the meantime, having a few backups of your current fave, you can leisurely find a future fave. I've learned in life not to worry about missing out on something, as there will always be more things to buy.