"Money pit" is one way of looking at it. "Knowledge mine" is another.

I agree that the bike is too small for you, but as I said in the other thread it's up to you if you are happy riding the bike. Just understand that when you get something else you should try something bigger.

You can do about 50% of all bike tasks with a 4-5-6 mm hex wrench like this:


If you have allen wrenches in these sizes, you can get by with those. Most of the other 50% requires some kind of special tool.

The nice thing about bikes is that they usually don't fail completely. Bicycle maintenance is usually a matter of getting things to work better or smoother. If you're willing to tolerate a lot of clunkiness, you can keep riding a bike that's in pretty bad shape.

Of course, if you put some things off too long it can do damage (mostly to bearing races). For instance, hubs that need to be cleaned and greased will eventually become hubs that need to be replaced, but if they are already hubs that need to be replaced you can ride on them as long as you don't mind the grinding feel.

The reason I mention this is that it allows you to acquire tools as needed and budget allows. I highly recommend putting off all tool purchases until you want to take on a task and are ready to spend the money on the tool. It sounds like you have general mechanical skills and are interested in getting to know your bike. Just understand that hardly anything is likely to be urgently needed.