first off welcome to the club, as an owner of several different makes of cars before i can say with all honesty that lexus is the best car i've ever owned and wouldn't buy anything else. i also bought a pre owned lexus and have been nothing short of amazed since owning it. i have had no major repairs and i'm already over 160,000 miles. as far as any major concerns regarding repairs you might want i would check if the timing belt has been changed and if it has was it at 60k or 90k miles. as far as the mileage 100,000 is just broken in with good preventative maint. you should easily get 200,000+ i wouldn't bat an eyelash and buy it you'll be amazed at the quality guaranteed