The premise that high mileage automatically means risky isn't quite right, but neither is the idea that maintenance records alone tell the whole story. A 2018 Civic at 145k is definitely workable - Hondas absolutely can go 200k+ miles without major issues - but what matters is the *pattern* of that maintenance, not just that records exist. Did someone do regular oil changes every 5k miles? Or were there long stretches of nothing followed by desperate fixes? There's a big difference, and service records can hide neglect if you only glance at them.
The one thing nobody's mentioned yet: get that pre-purchase inspection (absolutely do this), but also ask the seller specifically about transmission behavior. Civics are solid, but transmission issues at 145k can cost you thousands to fix and aren't always obvious in a test drive. Ask them point-blank if it's ever hesitated, slipped, or felt rough shifting. You should also check when the last major fluid changes were done - coolant, brake fluid, transmission fluid. If those are due or overdue, that's a red flag about overall maintenance discipline, even if routine stuff was done.
At $8,500 on a tight budget, this car could be a solid buy, but go in with eyes open about what repairs might be lurking. Factor in maybe another grand for things that might need attention soon, and you've got a more realistic picture of the total cost.