They can eschew immediate gratification and stoically live without luxuries for long stretches of time, all the while gathering up more and more money. If it gets altered or damaged, you'll never be forgiven. Earth signs see money as security, stability, and independence. They don't respect people who are financially irresponsible or deeply in debt. Gemini, Libra, and Aquarius.
Air signs can be very eccentric about money.
No matter how much cash they accumulate, they may forget to pay their bills. Practicality isn't their priority. These intellectual, inventive people create and develop million dollar ideas for the pure joy of adventure and experience. They don't live for money and security like the earth signs do. From a security standpoint, an alliance with an earth sign could be beneficial for an air sign.