Cheap bike tools or can I just use generic hardware store tools instead? I want to maintain my bike. There a number of tools which are very specific, which also cost a lot of money. I have an old road bike which uses a freewheel. The freewheel remover cost me something like 7$! This really seems overpriced. 

It would be nice if we had some sort of tool translation thread. Like, "these are the generic tools you would use in place of each of these specific bike tools."

Personally, I'm looking for replacements for the following:


The tools used to remove the bottom bracket.
The cone wrench, or the necessary tools to clean the hubs. By the way, do they have adjustable versions of the cone wrench?
The necessary tools for taking apart the headset. I've never done this. Maybe it can be done with generic parts?
chaintool?
anything else?


Maybe you really do need the bike specific tools for some of these. Oh well :(.
You are in luck! There are tons of threads on many forums talking about this very thing. However, I'll give you a head start.


You can use a vice-grip type wrench, but try to get something in between the wrench and the BB cup otherwise you risk damaging the exterior of the cup. I recommend ponying up the cash for a BB wrench, it's worth it.
While cone wrenches are nice because of how narrow they are, you can usually get away with any type of open-ended wrench. I've used an adjustable crescent wrench to great success.
This depends on the type of the headset, as noted in the comments. However, if you're looking to just pull bearings that's not too bad and you can probably tap them out with a screw driver, tire lever, etc. To pull the cups you can make your own tool from a piece of pipe by cutting some slits and bending it out. Might not be pretty, but it works.
Chain tools are cheap, buy one. You could try to clamp the chain and drive out the rivet with an awl or punch but you probably risk damaging the chain enough to need to replace it.
Here's where some searching will net you more. Check out BikeRadar, PinkBike, mtbforums, etc. for a lot of insight into homemade tools or alternatives. That's how I found out how to make my own headset press (granted I bent all the washers, but it worked and $15 of hardware is better than a $70 press).


It really comes down to your own cost/payoff evaluation. If you thought $7 for a lockring tool was expensive, you're probably not going to buy any bike specific tools. But you're also going to spend a lot more time cursing and nursing sore knuckles from having wrenches slip or tools break. Some tools will last a long time and won't need replacing (chain tool, wrenches) while some are only-if-you-want-it like a torque wrench.