Explain why it would cost more money to keep you than it would to have you stay. For example, you make $100 doing the work that a $40 person could do. Plus, yo

Explain why it would cost more money to keep you than it would to have you stay. For example, you make $100 doing the work that a $40 person could do. Plus, your bonus is 20% of your salary and comes due in 4 months. Then, performance reviews are coming and if your annual adjustment kicks in, based on performance, your cost is only going up. Additionally, you've been in role for 3 years and are looking for a path to the next level, because you've topped out in your role and pay grade. Also, if you're aware of any impending headwinds, site the mutual.benefit of said solution (cash flow is tight, the last several quarters were soft, etc.) Do all the math and then ask if there's a better way to part on good terms, at a specified time, for an agreed upon rate. However, before having a conversation like that, realize it might just be the fast track to getting fired.