Aquarium Rocks On A Budget?

I am working on a new aquascape for my axolotl tank and I am looking for some aquarium safe (obviously) rocks with character. Something like DragonStone with unique shapes and structures. What are some good websites or cheap sources to find rocks?

 

lava rock is awesome. it is red, pourus rock found in yards and gardens commonly, and it is pretty cheap. pool filter sand looks awesome, and is 5 bucks for a 20 gallon bag. the red rocks and the sand set off to bright green plants and colorful fish would look incredible. if you have a pond or lake nearby you can find some there. Just make sure there is no calcium in the rocks.

 

I like the look of lava rock and that its cheap, but I have heard very differing opinions about whether it's actually safe for axolotls which makes me scared to use it.

 

I would say something similar to texas holy rock (both dragon stone and lava rock are going to be tough on the skin of the axolotls). Some smoother type of stone.

 

I looked it up and it looks great. Im definitely going to try and track some down. Thanks for you help.