You CAN get a great sounding violin on eBay for $200, but you might have to buy and return a couple dozen violins to end up with one you like. My story is, that for my kid, I bought a $5,000 violin from a dealer after doing blind testing among a range of violins with ourselves and my kid's high-powered teachers. Everybody agreed that this was a great sounding violin. A couple years later, I wanted a cheap violin for myself so I bought a $200 violin on eBay. It arrived with a fallen soundpost so I needed to take it to the violin store for them to reset it for $15, plus, I put new strings on it for $40. I ended up selling that one and buying another $200 violin, which needed a new bridge, which costs about $75 at the local violin shop. I didn't want to spend so much money for each of the violins I was trying, so instead of getting it fixed at the shop, I ended up learning how to shape a new bridge myself, to save money. What followed was a couple year period where I bought and sold about two dozen $200 violins. I would buy them on eBay, fix them up into playable condition, and resell them from my home via Craigslist.
So, the buyers would come with their own current violins and I would put my eBay specials AND my kid's $5,000 into the mix for the blind sound tests. The $5,000 violin was always one of the leaders but not always the winner.
Eventually I settled on a single violin that I liked the best to keep for my own. I took it to the violin shop where people had much more skill than me and spent about $600 to get a nicer bridge, soundpost, and for some repair work that I didn't have the skills to tackle. So, yes, I got a great sounding violin for $200, a couple years of trial and error learning, and then another $600 for rehab.