You have a Large Format camera? Do you get paid for any of your photos, or do you upload to rootminus1 for free? You're right about the aperture settings though. My D70 can't make that photo look sharp, especially since there will be vignetting at the smallest apertures. How much does a 4x5 with three good primes (they don't even make zooms for a 4x5, do they) cost?
Depends on the makes and type of cameras. You can get good used field cameras with a couples of films back and a standard lens for around $1000 or a bit more, and the price can climb really high pending the lenses that you want. And, rail cameras are even pricier.
In the early 90s I got a good deal on a used Tachihara field camera with 3 lenses for $3000 CAD. However, it wasn't my favorite thing to lug around (camera gears was around 40 lbs large format, 35mm system, tripod, and food/water) even those the prints look great. Another caveat is that each sheet of film is about the same price as a roll of 120 film and I have to use 3 sheets for each shot (+/-1 stop bracket), and I get 10 shots out of a roll of 120. Also, the lens are not anywhere as sharp as 35mm (35mm sharpest, then medium format lens, then come up last is large format).
As time goes by I find that I uses my Mamiya medium format much more over that of the large format because of portability (about 95% more), and the mamiya optics are super when coupe with 25~50 ISO film, therefore I sold my Tachihara for the same price I purchased it for.
Cliff note, Get a Medium format camera and your back will thank you, and you will also enjoy it much more than the large format. The Mamiya lens are of very high quality comparable to the 35mm lenses therefore you don?t give up much compromise when choosing med over large.