Ever since the local supermarkets stopped using metal milk crates (those plastic ones just aren't worth a damn) I've been at a loss when it comes to finding a reasonably priced and well made LP storage system. Granted the metal milk crates were rather cheap, basically free at those after midnight sales events, but some of the prices charged by the custom furniture builders are simply outrageous. As my dear brother would say "They're not afraid to charge."
Along with the occasional hand built crate I've managed to slap together, I've also had some pretty good luck with the Swedish furniture megastore Ikea over the years. Their bookcase line "Bonde" is large and strong enough to fit and hold plenty of LPs. The only drawback has been its unavailablity for the past few years. However, that has now changed and the "Bonde" units are back in stock and available again. Check out the Ikea web site (www.ikea.com).
Note that on the "Bonde" units the bookcases can come configured into what look like equal squares, for lack of a better word. Well each of these squares holds about 80 LPs so the $100 bookcase with 4 such "squares" will hold about 250 LPs and look pretty good too. Not as good as a metal milk crate but you can't have everything.
By the way, my 15 metal milk crates are stacked 3 wide by 5 high and are in a corner of the room with a nicely finished wood board mounted on the one exposed metal side. Most people have no idea that there are these metal ugly metal crates holding hundreds of my quaint vinyl LPs.