I've gladly done this for several friends over the years. And, it's surprising what you can find on the very low end of the market these days. Yamaha has some fantastic cheap guitars, for example. $200-$300 will get you a new, entirely playable, acoustic or electric guitar. I have a $2000+ Gibson J45, and I often play my girlfriend's $250 Yamaha...it's really not a bad guitar, at all. I have no real complaints about it; it obviously isn't as nice as my J45, but hell, it cost a 9th as much (she actually got it free...someone who moved out of an apartment left it behind).
Having an experienced friend with you will help make sure the instrument is setup correctly (that can be an issue, and you shouldn't buy a new instrument that isn't), that it sounds nice and plays comfortably, etc. There is some variability in quality across instruments, and they're made of natural materials with variable densities and characteristics, so even if you read a bunch of reviews and go buy the best reviewed one, an experienced friend can help pick the best one of that model in the store.
This happened to me with skating. $35 Wal-Mart board, 2x as thick and heavy, junk bearings and wheels. When I stood on it and it barely rolled, I decided skating wasn't my thing.
So I suppose the lesson is: if you're serious, have someone who knows what a guitar is supposed to feel and play like if you're going to pick one up used. I've bought a 30$ electric that I still own and play, and a $100 one that was total junk because I hadn't handled enough guitars at the time to know better.
I don't think that's true for a beginner who can't really tell the difference, and I think that's also a discouraging sentence for people who are wondering if they should try learning guitar.
Yup. My first (and only!) guitar is an Ibanez Gio. I paid $55 for it and a practice amp. The amp sounded like garbage, but piped through a $100 Peavey Vyper or through Rocksmith and it sounds pretty good.
But I'm an extreme noob. I imagine an experienced player could pick up on all the shitty sounds it produces. The only time I ever notice it sounding bad is when the strings need replacing and the pitch of a note wobbles all over the place and they go out of tune in 15 minutes of playing.