Going out and buying a DSLR as a first "serious" camera is a bit like making yr first car a Ferrari!
False. This is what the 'macro' mode is for. Macro photography is relatively easy to get started on a DSLR. Or it's not any harder than a point n shoot.
Your the only person I've ever heard of that shoots sigma lolOh, and yes you are correct there are a lot who go for canon with the MPE-65, but quite a few get that type of magnification much cheaper. I know a couple that make money off their shots and they use very humble setups (bellows for example). Likewise, the holy grail of 1:1 macro lenses many consider is the Pentax FA* 200mm..... just saying
Define "almost any brand of manual lenses".... do you mean like manual as in modern manual focus lenses such as voigtlander?
Sigma has a unique sensor that is arguably the best at providing per pixel detail.
50mm macro, 105mm macro, 150mm macro
For expansion of the system, Canon currently also has the best options and accessories:
ring lite, twin lite, extension tubes, 180L macro,
100L IS macro 100/2.8 USM macro, 50mm macro, 'life size converter', 60mm EF-S macro, and of course the
65mm MP-E (1x-5x).
The only other more comprehensive macro system that I know of is from the old Olympus OM system.
20/2 macro (roughly 3x to 15x), 38/2.8 macro, 50/3.5 macro, extension tube 65-112mm, auto bellows...and so much more that I don't care to list.
...and to me the 'holy grail lenses at 1:1 are either the
C/Y zeiss 100/2.8 or the Leica R 100mm macro...
Bolded items are items I have or have used.
As for the other brands that I've mounted on Canon EOS:
Olympus OM (as in bolded above) via adapter
Leica R - via adapter
Pentax K (as I mentioned before)
C/Y Mount Zeiss
Hasselblad C mount (also Zeiss via Zork shift adapter)
Sigma (of course)
Zeiss ZE mount
Contax (adapted to EOS mount by conurus)
...and I'm probably forgetting something
Back to Chase's question...sort of at least.
Canon used bodies can be had for cheeeeap. I just bought an original Digital Rebel for $190 (used of course). Paired with a used Sigma 105mm($400) or 50mm (~$300 new) and a set of kenko extension tubes ($130)...a very flexible macro kit can be put together for about $600...less than that if all pieces are used. In Canon mount, all of these items are easy to get used in excellent condition.
Chase, I guess it all depends how far you want to go...