Here are two tips to follow when shopping for a new instrument at a music store.
Patiently wait for instrument sales to take place if you want a high-quality instrument
When purchasing an instrument, it's advisable to buy the highest quality version of the one you want. A well-made instrument could not only have a lifespan of several decades but, even more importantly, will produce sounds that are far superior to its low-priced counterparts.
This matters, even if you will only ever play it for yourself and your loved ones, but is especially significant if you are planning to regularly use it when you perform as part of, for example, a quartet, an orchestra or a band, as the quality of your instrument's sounds will have a profound effect on the quality of the group's overall performance.
However, the best versions of, for example, a violin or a guitar can cost thousands. If you cannot spend this much, then it's best to be patient and wait for your local music stores or online instrument retailers to run sales, as businesses like this may discount their best instruments quite heavily during their sales. Waiting for just a couple of months for a music store to run a sale could allow you to acquire a version of the instrument you want that produces exquisite sounds when you play it and which is likely to have such a long lifespan that you might even be able to pass on later.
Find out in advance how to take care of the instrument (if you're not familiar with it)
If you're going to buy an instrument that you've never played before and don't know much about, you should spend the period in which you're waiting for it to go on sale learning how to take care of it. For example, if you're going to buy an oboe, you'll need to oil it regularly to prevent corrosion that might affect the movement of the keys, and you'll need to clean it with polishing cloths to maintain its shine and to ensure that dust doesn't build up in its components.
Finding this out before you find the instrument you want goes on sale and ensuring that you've got the items you need to perform maintenance on it will mean that when you eventually purchase the high-quality version of it, you'll have the knowledge and accessories you need to take excellent care of it.