Yes, tooling is that expensive
Though that sounded like a MSRP, rather than the actual street price.
I pretty much never use insert tooling. I purchased a cheap import insert boring bar from Ebay, and made my own for outside threading. I do plan to upgrade the internal bar at some point with a quality one. Threading inserts are a good idea for the hobbyist imo since they basically never wear out. I also made a dovetail cutter that takes inserts for the mill.
I use one variety or another of HSS for pretty much everything else on the lathe.
On the mill, if there is anyway to flycut it, I flycut it. I save my endmills for when there is no other good option.
I have been slowly replacing some of my endmills with solid carbide ones (mainly steel cutting ones). MariTool seems to have good prices, and they are USA made. It is definitely worth the difference in price between carbide and cobalt when machining steel. I find that a quality cobalt tool is better than an average carbide for aluminum - so I plan to stick with cobalt for that. Avoid cheap import HSS for aluminum, even the coated ones have galling issues from poor finish quality in the flutes.
You will probably hear it many times, invest in a grinder and learn to grind your own tooling. Not only will you save hundreds of dollars a year on tooling, you will have more flexibility in your work. Get a decent 8" grinder (Delta from Lowes is fine), and drop the dime on quality Norton white wheels (can cost more than the grinder). A set of DMT combination diamond laps (so you can touch up your brazed tooling as well), and you are good to go. You don't need a fancy tool rest, freehand grinding looks more scary than it is. The whole set up will cost less than a pair of insert tool holders. I suggest plain HSS for brass/aluminum, 8% cobalt for steel, Rex (or some other "super" HSS) for cast iron, heavy scale/rust/pits or deep roughing. You can safely turn light blue chips with a Rex bit, and dark straw to light blue with 8% cobalt. The really nice thing about 8% Co and Rex tooling, is that they do not require the tool pressure that carbide does, so you can take extremely light cuts on steel that would require special carbide inserts to make, they are also about immune to interrupted cuts.
