How much it's collected the artist and how many copies have been printed of each vinyl?
This first point it's very important cause there are very collected artists like Beatles, Queen, Pink Floyd, U2, Iron Maiden, Rolling Stones and so on... that solds a lot of copies of their albums and singles, so if you have a vinyl of Beatles that was printed in only 100 copies and it's not a reprinted but it's an original issue, probably you have a really hard to found and highly worth item. While if you have a vinyl of another artist that it's not very known and not collected it will be not worth a lot for the simply cause nobody it's interested on it.
I have a lot of very old records? surely they are worth a lot of money!
I think anyone who buys and sells used record has heard this phrase at least once in a lifetime, so i think we must clarify this concept. Even if there are old vinyl that are worth a lot of money and cause they are old are probably harder to found and in good condition, we must return to point 1, it depends on artist and how many copies there are of it, age alone doesn't mean it is a rare item. There are many vinyl printed in the last 10 years that are worth a lot of money cause printed in few copies, limited editions, special editions and so on...
Promotional items, special editions, limited and numbered editions
In the vinyl market there are many items that were used for promotional purpouse and never sold in the record shop. Labels gives this item to Radio or Press to promote a new single or album and this items are most of the time in a very limited number. The same goes for numbered editions or special editions, like picture discs or coloured vinyl that are usually printed in few copies. Of course 1000 copies for an high collected artist/group are very few respect to another artist that is moderately collected.
So what i need to know to worth a vinyl more than what we discuss above?
Well here there are some of the things you must to revise before to buy a vinyl:
I realize that most of the people even if they control all these data have still no idea of the real value. In the past the only way to have an idea of the value of an item was to check it in a Record collector price guide book or magazine, or through records fair, where you can see items like yours and ask to seller the price.
Nowadays it's more easy cause through internet you have many options:
Nobody can give you a real value of an item, in fact if you go to a record fair or check in some online shops or marketplace you can see the same item at different price. This may be becaus of different conditions of each items or cause a seller want to sell the vinyl at an high price or nothing cause has a sentimental value or need money so prefer to sell it quickly so decide to sell it at a lower price.
So in my opinion, once we know that the vinyl we have it's an high, medium or low valued item
we have 2 options to sell it quickly and at areal market price: