If I'm interpreting correctly, your in the UK. Doing the conversions, the price that you've found for LR is about $8.50 USD/lb. That's extremely reasonable for true indo-pacific live rock.
If you are a beginner, I cannot more strongly recommend that you start with natural Indo-Pacific live rock. You can also start with Florida aquacultured live rock if it's readily available in the UK - this material is natural rock that has been setting on the ocean bottom for 20 years.
I would advise you to stay well away from man-made rock. It simply doesn't have the porosity that natural rock does, whether that natural rock is so-called "dry live rock" or natural live rock. Some of it is made with thorite (or "hydraulic" cement) that contains a large amount of alumina-silicate minerals, and neither the aluminum nor the silicates are ideal for a marine reef tank.
It is, by the way, untrue that responsibly harvested natural live rock is highly damaging to a reef ecosystem. On the coral islands of the Indo-Pacific, many hundreds of thousands of tons of it are harvested every year to build roads, buildings and breakwaters. Usage for the aquarium trade is absolutely tiny in comparison, and the material is typically harvested from the surf zone, not the reef.
The reason that it isn't as available as it once was has to do with CITES (Convention on International Trade in Endangered Species). Island nations that supply living coral for the aquarium trade have quotas for the maximum amount that can be shipped each year. As far as CITES is concerned, a piece of live rock counts the same as a living coral. Because living coral is far more profitable than live rock, places in the indo-pacific with collection stations, airstrips and mariculture operations choose to fill their quotas exclusively with coral rather than live rock.