Originally Posted by smd4

And now I think I need a pliers wrench.

Originally Posted by Koyote

Haha, ditto.

This is also useful if a person doesn't have really good screwdrivers.

Originally Posted by smd4

I've posted this before, and I'm not sure it meets the "budget" requirement, but still think it's a pretty good list of tools that would be useful in most home shops:

I'll preface this by saying you may already have a lot of these tools in your home tool box. Also, lots of these tools might not be necessary for modern bikes. Allen keys, for example, seem to have been replaced by Torx. Anyway...

--Set of metric open/box end wrenches up to 17mm;
--12" adjustable ("Crescent") wrench;
--Ball-peen hammer;
--Metal shop ruler (to measure chain stretch, etc.);
--Needle-nose pliers (to grab the cable when adjusting derailleur cable length);
--JIS (Japanese) Phillips head screwdriver, probably No. 2 will cover you in most instances;
--Hex/Allen Tri-wrench in 4, 5, 6 mm (Without doubt the most useful tool in my toolbox);
--Socket Tri-wrench in 8, 9, 10 mm;
--Torx Tri-wrench (I have one but don't use it, because I don't have any Torx fasteners);
--Pedal Wrench (I have an older (Verma?) model that has both 15mm and 1/2" at either end);
--Set of good quality cone wrenches (I use Park);
--High-quality spoke wrench to fit your spoke nipples. Park makes these. Get the kind that looks like a hot-air-balloon with rubber grip. Don't cheap out on this tool!;
--Headset wrench specific to your headset if you use one. Park makes these as well;
--Chain Whip;
--Cassette lockring tool depending on cassette manufacturer (This will be used in conjunction with your chain whip and adjustable wrench);
--Bottom-bracket tools, depending on what you're using and the era;
--Fourth hand (Hozan makes the best one);
--Quality bike-cable-specific cable cutters (I use a discontinued Shimano version but the newer Park one seems quite capable--and the high-end Knipex from Germany are amazing and feature a cool cable end crimper);
--Metric Allen key set (the "L" shaped ones);
--Chain Tool (type depending on what you use--rivets, quick links, etc.);
--Tools specific to your bike--I need an extra long 6mm Allen key for my stem and an 8mm Allen for my cranks. I also have a specific tool for my chainring bolts and crank dust caps, and one to adjust my pedal bearings;
--Good quality oil (your choice; I use Tri-Flow);
--Good quality grease (your choice; I use Shimano Special Grease. Phil is good too);
--Good quality floor pump including good-quality chuck for your particular valves (I use a Silca Pista Plus with Hiro chuck for Presta valves);
--Tire valve core tool (I think these would be used if you are tubeless and need to remove the valve core);
--Decent floor stand if your bike can be lifted into one;
--Torque wrench if you're dealing with a lot of CF that requires specific torques, or you just don't trust yourself. A beam type should suffice.

Fun tools but completely unnecessary: Angle gauge; digital bike (expensive) or luggage (cheap) scale; digital caliper.

This list is what I can think of off the top of my head, but should be a good start for most home shops. YMMV. There are of course very specialized tools like dropout alignment tools, headset cup and race removers/installers, etc. These can be pricy and not used very often, but many can be fabricated at home. I may add to this list as I think of things.

Originally Posted by smd4

The article is behind a paywall, and the farthest I can read before it blacks out suggests that while JIS isn't obsolete, it's been rolled into an international standard.

I have a JIS No. 2, which seems to fit everything from the smallest derailleur limit screws to much larger Phillips heads around the house. Almost like a one-size-fits-all, and it fits everything really well!