Sonicbeauty: I have come across a dealer selling gear that they claim have full manufacturer warranty on them. What if you find out from the MANUFACTURER that this dealer in question is not an authorized vendor? Would you buy anyways?
Let me begin by asking you for some quick advice first myself. Sometime ago I saw something on a shelf in in a some shop. Should I buy it? :-)
Seriously, this forum is about information exchange and just as we expect to receive help from the knowledge pool here, we should contribute to it by giving precise information: product, manufacturer name, dealer name, price offered. Needless to say, this will also bring in more precise and informed advice.
There is nothing wrong with buying from unauthorized dealers as long as you know what you are getting and it is priced accordingly. Good dealers will not lie about being authorized. Items that are "B stock" or "Refurbished" will be marked so and not offered as new A stock. The vendor will likely offer their own warranty. Should you trust it? Depends on the product and the vendor.
Some vendors have earned our trust: personally, I may hesitate with someone totally unknown, but I would consider a warranty from respected names like J&R, or my local Audio Consultants and Saturday Audio. However, I would also factor in that certain products may be easy to repair at a generic but competent shop (for these, even manufacturers may use a local shop for warranty work); others, especially new complex designs, are best shipped to the factory. That is why precise details are important.
If the vendor's warranty does not inspire confidence, then you should regard the item as not only "used" but also "as is", and buy only if it is priced accordingly.