How long will you live there? Generally 7 years is a good rule of thumb for rent vs buy. Selling is more hasstle and expense. 7 years of no rent increases (read inflation, and your raises) and some principal paydown mean typically your have done better. However that is a guess. Sometimes even one year is better to buy, sometimes 15 years is needed (new roof and other major evpenses) just to break even.
They can’t: the speed of light is so slow that they don’t even know we are here yet. even if they are in the tiny zone where we are detectable with arbitary technology, they can’t get here in your lifetime because the distance is so large. they have to get here because to cover all sides of a round planet needs something on all sides since many useful frequencies don’t go through the earth, not to mention they don’t have enough energy available to pull this off from their home., there are a few more reasons this is impossible that I’m not aware of.