There is a popular misconception that an old violin is better than a new one. This is only true if the old one is in new condition, has all the right measurements, has never been tampered with by some inept tinkered or “mechanical”, and has great sound. It is next to impossible to find a violin over eighty years old that hasn't had the top removed, the bass bar replaced, the neck reset, cracks repaired and a host of other things done to it. The extremely expensive Stradivaris, Guarneris, Amatis, Pressendas and such are more likely to go to a capable repairman, but the majority of old instruments have been meddled with by a surprising variety of handymen, with woefully inadequate experience or training. Good outward appearance is no guarantee of condition. If you're buying an old instrument, insist on having it examined by a recognized expert. Even an expert may sell an old Junker to an eager victim for a high price. There are many big name instruments with bad measurements, pinched sounding notes or nasal tone. The performer feels playing a famous named violin lends prestige, so tries to ignore minor problems. The practice of thinning the top to make the tone ‘mellower' (soggy) has ruined many good instruments for the collector as well as the player. Your bow is subject to these same hazards, too. Don't get it rehaired by an amateur.
A new instrument if made right, has nothing wrong with it that some vigorous playing won't cure. It has correct measurements, good intonation and appearance, but must be played before it will have more volume and beauty of sound. If you don't leave it in a damp location or a hot place (especially the car trunk) it will probably be very free from problems. With playing, the new one will get louder, respond easier, and have more beautiful tone quality. Only minor adjustments to the bridge or soundpost are occasionally needed. A wide variety of prices are asked for new instruments, according to beauty of wood, finish, tone quality and fame of the maker. A good commercial violin may sound better than the more expensive one (or old one), so try them. You can get a better idea of the quality by listening to someone else play it. Try to buy from a violin dealer or importer rather than a music store only. You'll get more help and better advice. When you get it, play the heck out of it for a while. The improvement will please you.