We are trying to decide how many multiplexed samples to use for a RNA-seq experiment. If we expect ~50M usable reads per lane and presume a 50K transcriptome to get ~1000 reads per gene, then 5 multiplexed samples would give 200 reads per "average" transcript. Is that level of coverage reasonable for differential expression analysis, or should we aim for higher coverage?
Just remember that genes have differing levels of expression; you will get a large proportion of your reads mapping to the most highly expressed genes.