That’s going to be near impossible to do. 25-50k on UA (mostly) BE and hitting SAG elsewhere. May I ask how you make Gold on UA? That requires $10-12k spent which with cheapest available/BE will be near impossible. Are you sure you are booking rock bottom fares? Can you post some common booking classes you fly?

Turkish is usually good for cheaper UA fare classes: https://www.turkishairlines.com/en-u...ited-airlines/
You’d still have to hit the thread hold for Elite Plus and if you are only buying 50% earning that’s not going to work.