As mentioned, modular furniture can provide a prety cost-effective and reasonable looking solution if your not prepared to go to custom built shelving. IKEA (http://www.ikea.com) offers some solutions that some have found work well. Look at the Bonde, Billy and Ivar series.
With the Bonde series, the trick is to purchase a combination of the 14x86 and 28x86 bookcases. These have shelves in 13" widths. They come in wood veneer, or white for a lesser price. See:
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00030064&type=III
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00030063&type=III
With the Ivar series, the trick is to buy separate 13" (approx.) shelves and 6' uprights. You connect them to form two columns of shelves. With each shelf at 13" wide, you don't have any sagging and you get good vertical support for your LPs. The six foot uprights easily allow for 4 shelves; to get 5 shelves you need to start with the first shelf on the floor. (The Ivar series is sold on a completely modular basis - you order it stick-by-stick to match your needs.) See:
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00005050&type=III
At one time, Ikea sold a line of modular 13" x 13" shelving that was a perfect inexpensive solution: the Expedit series. It never appeared in their website, but was available in the stores. I don't know if it might still be available.
With the Bonde series, the trick is to purchase a combination of the 14x86 and 28x86 bookcases. These have shelves in 13" widths. They come in wood veneer, or white for a lesser price. See:
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00030064&type=III
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00030063&type=III
With the Ivar series, the trick is to buy separate 13" (approx.) shelves and 6' uprights. You connect them to form two columns of shelves. With each shelf at 13" wide, you don't have any sagging and you get good vertical support for your LPs. The six foot uprights easily allow for 4 shelves; to get 5 shelves you need to start with the first shelf on the floor. (The Ivar series is sold on a completely modular basis - you order it stick-by-stick to match your needs.) See:
http://www.ikea-usa.com/product_presentation/show.asp?productnumber=00005050&type=III
At one time, Ikea sold a line of modular 13" x 13" shelving that was a perfect inexpensive solution: the Expedit series. It never appeared in their website, but was available in the stores. I don't know if it might still be available.