I worked in the business for a couple years, and really began collecting seriously then... now the stuff is hard to move key. set low expectations on price.
i had over 15k worth of stuff at fair value, I been selling it here and there when I can... will probably get around 40-50% of that when all said and done. some were just bad buys on my behalf but others were not but still hard to move.
Muhammad Ali, Larry Bird, MJ, Dr J, Ted Williams were my bigger pieces.
Still have the Muhammad Ali, I should try to move that.
Anyways, your authentications are everything. If you don't have them on expensive pieces, you could look at PSA/DNA. Most brokers wont accept autographs that don't have one of the big name authentications.
If you have all the authentications already, find your local place and ask for a consignment deal. I usually offer them 25-35% of the sale price. Often they want more, so make sure you try to negotiate it all together as that helps. But even at 50% sometimes its a good deal.