I used to drink tisanes (herbal teas), and then switched to just conventional tea for a few years, but I've been getting back into them a little. For me the nicest benefit is you can drink them in the evening, and I shut off black / oolong / green tea drinking in the afternoon so I can sleep at night.
About the last question about what types there are, that are affordable, there are almost too many. In general I'd avoid drinking anything that comes in a tea bag these days (sort of how tea enthusiasts do it), including tisanes, but this past favorite brand gives an idea of scope, and information about one source cost:
No need to make it more complicated than it is; put whatever you think would make a nice tea in hot water, leave it sit for 4 or 5 minutes, strain and drink it. Depending on the ratio of herb to water it may well work to use more herb, relatively, and multiple steeps instead, continuing with longer ones until it stops tasting nice.
In general people drink blends, mixes of lots of things, or floral teas (many), herbs (overlapping with spices), in addition to teas made from all sorts of dried fruits or berries, roots (ginseng is one), bark (cinnamon is that, but it's not common as an unmixed tea), or whatever else. My favorite was sage, just like the herb used in stuffing, and lately I've been drinking that, as well as rosemary, just the herb made as tea, and mulberry leaf tea. This is a recent blog post I wrote about the sage, what it tastes like, and a bit of research on health benefits (alleged benefits--who knows really), but to be honest it's just sage, everyone already knows what it's like:
http://www.tching.com/2015/11/review-sa ... -infusion/