If you are paying $300/day for a DVX100, you are getting screwed.
I do a ton of freelance work and own a DVX100. Granted, I can only shoot SD, but it’s paid for it self at least 5 times. I would highly recommend purchasing a 3CCD camera along those lines. If you shop around, you can get a lightly used DVX100 for $1000. A few jobs and it’s paid for.
For higher end shoots, renting is the only way to go. But you should definitely own a good tripod and always bring along things you think you might not need (i.e. gaff tape, extra tapes, extra mic cables, etc.) You can never be over prepared.
I do the full-time corporate editing gig, but the money is in the freelance jobs. Just make sure you make your clients happy because there are people who will do this work for next to nothing these days.
Brian