Yes there are DIY live rocks called aragacrete. The problem with them is that you have to cycle them for at least 6 months to bring down the ph to a more stable level.
Just as the name suggests, it is made by mixing aragonite sand, some plastic fibres and concrete. It is a practical choice for people who pay a lot of live rocks. We pay anywhere from $7- $10 per pound here, so it makes sense to culture your own.