It would be nice if marrying an attractive woman were this simple and could be bought with specified terms or conditions to be crafted in advance and agreed upon.
For example,
1. I will maintain sub 4:40 mile fitness until age 40. Sub 5 mile fitness until age 45.
2. My body fat will not exceed 10%. BMI not to exceed 25.
3. Gross income in the next 10 taxable years must exceed $110,000.
If at any point the terms aren't met, this will be considered a breach of contract and you can walk away