I completely understand.
In this case I'm going to suggest buying a
kit. For instance,
look at this one on EBay. It will display frequencies from 1Hz to 6MHz.
Note that it's $29.96 USD. You'll end up spending more than that buying the parts separately. And you'll still need a printed circuit board (PCB).
Maybe not exactly building one from scratch (which is by no means easy), but the process of building it would give you excellent experience in constructing an electronic device and you would have something that you
built yourself.
And it ships from Hong Kong, a lot closer to you than it is to me...
And, of course, you can come back to ETO with any questions/problems that may arise!