A salary hike often feels like a reward for years of hard work. For many people, it triggers thoughts of a better car, a bigger apartment, or lifestyle upgrades that seemed out of reach before. But what if that extra income could quietly become the difference between having a few lakhs and building serious wealth? According to Chartered Accountant Nitin Kaushik, one of the biggest financial mistakes people make has nothing to do with how much they earn. It has everything to do with what they do after their income increases.CA Nitin Kaushik recently took to X to highlight what he calls a silent wealth destroyer: lifestyle creep. In his post, Kaushik explained that when salaries rise, many people immediately increase their spending. A new vehicle, higher rent, more expensive vacations, and upgraded lifestyles often consume most of the additional income. Meanwhile, investments remain unchanged year after year.He argued that this habit quietly erodes long-term wealth creation. According to Kaushik, many investors start a Systematic Investment Plan (SIP) and then leave the amount unchanged for years. While that approach still creates wealth, it may not be enough to keep pace with rising aspirations, inflation, and increasing earning potential.SIPTo illustrate the difference, he shared a simple example. A monthly SIP of Rs 10,000 invested for ten years at an assumed annual return of 12% grows to roughly Rs 23.2 lakh. On the surface, that appears to be a respectable corpus. However, Kaushik pointed out that the purchasing power of money changes over time, meaning that what looks substantial today may not feel nearly as impressive a decade later.— Finance_Bareek (@Finance_Bareek) The real opportunity, he said, lies in increasing investments as income grows. Instead of keeping the SIP fixed, Kaushik suggested raising the contribution by just 10% every year. In this scenario, the same investment journey over ten years results in nearly Rs 33.7 lakh.That creates an additional Rs 10.5 lakh compared with maintaining the original SIP amount throughout the decade. The difference is significant because it does not require extraordinary investment returns or risky financial products. The only change is a small annual increase in the amount invested. Kaushik described this extra wealth as money that might otherwise disappear through unnecessary spending. Rather than allowing every salary hike to be absorbed by lifestyle upgrades, he believes a portion should automatically flow into investments.His broader message is that wealth creation is often driven less by dramatic financial decisions and more by consistent habits repeated over long periods. Incremental increases in investments may seem small in the moment, but over time they can produce outcomes that are far larger than most people expect.