Jeffrey - I have not tried it, but I don't put a lot of stock in an online or DVD course for singing because learning to sing is a very personal journey and you need real feedback from someone who knows what to listen for and be able to tell you how to work on the problems. you won't get that from DVDs or the internet (unless maybe you do it via webcam or something).
I decided I needed to learn to sing better, so I took voice lessons from a local community college. they're really inexpensive that way compared to taking private lessons from an individual and you get good classical training in most cases as long as your instructor is good.
I took 6 semesters of private voice lessons under the same teacher. She was the best one at the campus and I learned a LOT from her. It is classical training, but you can always use classical training to transfer to ANY genre. The classes required solo performances in front of other teachers and peers and I think that was a very important part of the lessons as well. I'm not sure you'd get that from regular private lessons.
Cost was about $150/semester and that will vary of course depending on the college. so for each 9 months of private lessons I paid $300. that's a bargain IMO.