Hi,
The 2080 has three trays, each with a capacity of 4L. I would look at the Fluval biomedia or the Bio-Life media just for price comparison. I suspect that the performance of the various sintered glass media are very close but that their pricing might vary considerably. Any of the ones that have the "mech" moniker in their model names are going to be similar. They disrupt the flow so that suspended particles fall out of solution and help to prevent clogging of the biomedia in the upper chambers/trays, although they may also host bacteria as well. Get the cheaper one.
The cost of a complete 2080 media set is £57. If you buy the 2080+media set at Charterhouse Aquatics the total package cost is £240. Serious dosh, I know, I know
Cheers,