Lower control arms cams bolts
These are about $10 a piece. You'll need four new ones. The problem here is they'll probably have to cut them off. I would imagine they want to charge several hours of labor just for that problem. The charge book might require taking the entire suspension apart, which would add many hours to a job that shouldn't take more than a few.
I can't remember the price of these, I but don't think much more than about $50 each. YOu need two. You can find them cheaper at a regular autoparts store. This part has little to do with adjusting alignment and would only affect it if they were actually worn out. Labor to replace them shouldn't be that much. Maybe several hours.
The dealer probably charges an outragous price for this part. You can find a very good aftermarket Moog unit for around $100-150 at your local autoparts store, or rebuilt it using factory parts.
Tie rod ends are probably a good $80 plus a piece from the dealer. You'll need four. I would aftermarket here too. Get Moog units. For the coupler, the dealer probaby charges outragous price for a new units. I doubt you'll find aftermarket versions of these. But any wrecking yard should have them. If you buy used tie rod assemblies, I would replace the tie rod ends with new ones. They may be expensive, but they are a critical safety steering component.
-Do I really need to replace all the above to get a proper alignment?
If the cam bolts and tie rod assemblies are rusted, which it sounds like they are, then yes, they cannot be aligned until replaced. If the ball joints were worn out, this could also affect alignment somewhat. But remember, dealerships are stealerships. I would get a second opinion.
-What are the nececities, tierods?
A worn idler arm will cause loose feeling steering, but doesn't usually break unless extremely worn out. The tie rod ends can break leaving you with no steering control. I would at least replace these, if they are needed. Ball joints can break and seperate, causing the wheel to fall off of the truck in extreme cases. It just depends on how bad they are worn out, assuming they are worn out at all.
-Is Toyota insane for wanting $2000 to replace the above!?
Sort of. As mentioned, a big chunk of the cost is parts. Toyota dealers waaaaay overcharge for darn near everything they sell. Some parts are worth paying dealer charges, some parts you don't have a choice, but other parts can be found in the aftermarket for much more reasonable prices and some parts can be simply rebuilt. Dealers also tend to charge much higher labor prices than independent shops. Dealers also tend to want to replace as many parts as possible to avoid any liability problems down the road. Especially when it comes to steering and suspension. I would at least get a second opinion from another dealer and/or an independent shop.
You might try pricing a regular alignment shop to do the work. If you go to an alignment shop, I would avoid the places that sell tires AND do alignments. They tend to hire less experienced kids that sell tires one day and do alignments the next. I would go to a shop that does only alignments. They are out there.
Good luck.