Building Maple stand need inexpensive wood supplier


I plan to replace my MDF shelves with Hardwood Maple. Prices on Ebay are high. Can you recommend a hardwood supplier with reasonable prices. I am in San Diego. 24x 18 x 1 1/2 to 2" thick.
kavakat1
Based upon the prices I have found, I am considering another material. Basalt pavers or slabs are heavier and higher density than granite.  They are light only on the wallet. I invite your thoughts and suggestions. 
I’m a big fan of Bluestone pavers. They sound wonderful with cones or springs.
Bluestone is a blue gray paver Stone that comes mostly from Pennsylvania that looks somewhat like granite and has high mass and stiffness, very desirable characteristics for audio. I get my Bluestone at Home Depot, in the garden outdoor section. A slab about 18x18 and 2 inches thick should do nicely.