Ka-bar's large "heavy" Bowie is one to consider. I think they made a mistake in naming it, since the blade is not really that heavy, and may actually be less heavy than many common production Bowies out there. It's got a flat grind, which makes it better at slicing than some other large knives, but it seems quite tough, and chops well. You can get one for under $50 delivered. Steel is 1085, I believe.
For a bit of a walk on the wild side, consider a khukuri. Go with Himalayan Imports (via the forum of that name under "Manufacturers" on BladeForums). Browse around the old posts a bit, and note that most days there are a number of their knives offered at a deep discount below the standard asking price. You can predictably get a good bush knife for $75 or less there (especially if you don't mind browsing and waiting for one that got a little rust during the journey from Kathmandu, or some other usually-cosmetic blemish). H.I.'s main website is here:
http://www.himalayan-imports.com/ ; links from there will give details of various models. The H.I. khukuris each come with a smaller knife called a "karda" for finer cutting tasks, as well as a honing steel, both of which fit into little pockets in the back of the khukuri scabbard. I'd suggest a British Army Service ("BAS") model as a starter, all-around bush knife. For a SUPER-tough one, consider the Chiruwa Ang Khola model (slab handled, blade usually half an inch thick at the thickest part of the spine, H.I. guarantees to the original purchaser that if this model is bent or broken, they will send TWO replacements; it's thick enough, though, that it can be awkward for some non-slicing tasks.) Himalayan Imports khukuris are hand-forged, differentially tempered (upper 50s to lower 60s in the main cutting portion of the blade, less hard elsewhere, to provide edge-holding as well as resilience), very tough (see reviews here, in which they leave other "tough" production knives in the dust:
http://www.cutleryscience.com/reviews/face_off_II.html
http://www.cutleryscience.com/reviews/face_off_III.html
http://funditor.110mb.com/Chiruwa Ang Khola Khukuri Review.html
http://www.outdoors-magazine.com/spip.php?page=article&id_article=72),
backed by a great guarantee; also, because they're hand-forged by expert craftsmen in Nepal, they've got a heck of a lot more "character" than anything you're going to get from a factory in New York or Taiwan. Oh: you asked about steel. The steel for these is cannibalized leaf-spring steel from trucks and cars that find their way into central Asia, and from old files and the like. I think the conventional wisdom is that it's usually something like 5160 steel, but I'm not sure.
For inexpensive, I've really never had any problems with Ontario's Old Hickory knives. You can pick these up on eBay in all kinds of sizes and shapes, and it's not hard to get them for under $3 apiece that way. They fill a niche of an inexpensive, tough knife that you can keep as a backup in case your $400 custom-made knife gets dropped in the lake or falls off a cliff.
Have fun!