The time and money you spend getting this bike "right" yourself is worth every penny, not just for the bike's worthiness, but for the experience. You'll learn a lot, period, and be glad you did, having spent what it costs to go to 3 or 4 movies and be a whole lot more entertained.
Plus, you'll have a smooth roller to ride.
When I get a bike, unless it's from a trusted BF member, I don't care if they say it was "just tuned up, lubed, and adjusted at a local bike shop." I double-check and make sure. If I can't tell it was done, I do it.
You'd be surprised how well a well-built bike will ride right up until the bearings are pebbles.
You'd also be surprised how much better it rides once it's actually serviced correctly.
Good luck on your bike.