Taxonomy, phylogenetics, morphology and DNA sequencing.

[DavidCampen]

First let me recapitulate my vague understand of taxonomy and phylogenetics (as applied in botany). Taxonomy is the classification of plants into groups according to physical characteristics of the plant(morphology) and perhaps also population groups and pollinators. A principal reason for doing this is the expectation that the groups delineated by taxonomic classifications will also indicate evolutionary associations (phylogenetics).

So, I am wondering about the current state of DNA sequencing of genes. How expensive is this now? It would seem that DNA sequencing would be much more informative and definitive than morphology in placing plants into taxonomic/phylogenetic groups.

Does anyone have information about this?