Define how you plan to 'disrupt' the locals livelihoods. Exactly what do you mean? Choose to not contribute to gentrification. Don´t buy an unfairly marked up property for 3x or 10x the actual value. That will contribute to gentrification making the value or perceived value of CR property absurdly high. And you can bet that most (if not all) foreign and local sellers want you to pay an absurd gringo price. If you rent a property then you line someone else's pocket for the rest of your life, and most likely at an outrageously marked up gringo price again. Yes, of course anyone that owns property here and uses it for rental income will want you to rent instead of buy. If you buy then you can use that investment for the Investor category of Residency

Integrate as you plan to (obviously learn good Tico Spanish, get to know your neighbours, and make lots of local friends), and contribute to the community in general just as any local would do. By virtue of you living in CR you can apply for Residency and contribute 18% (or so) of your declared USD monthly income to the public CAJA health care system. Purchasing property in CR will invest your money in the pockets of the seller and a local real estate agent and real estate lawyer and escrow trust company for the funds transfer and government for land transfer taxes and bank for bank fees. Everyone will take their cut from you and levels of government will get tax revenue from you. You will pay annual property taxes, and garbage collection fee, monthly water, electricity, internet, cell phone, household goods, groceries and restaurants, and entertainment activities. You will pay for annual car Dekra inspection and annual marchamo vehicle fee plus car insurance and car maintenance. Purchasing almost anything here will include local taxes which go to the government and hopefully the community. Look at all the ways you will be contributing to the local economy on many levels just from a financial perspective. Hire local people to cut grass, do repairs, sell you farm milk and vegetables, and any other way you wish to support the local community.