This depends on the number of samples you have, your budget, and your biological question.
Typically, we offer two different packages for bulk RNA sequencing: STANDARD with 10 million sequencing reads per sample, and PLUS, with 20 million sequencing reads per sample.
Even bulk sequencing data can be noisy. For downstream analysis, it is usually wise to have triplicates or at least duplicates. In any case, we always recommend you include at least a second vial for each of the samples you send, to make sure we have a technical back-up.
We use BWA or STAR for mapping the data and DEseq2 for differential gene expression analysis.