Honestly, you can buy a used starter's microscope for less than 100 euro. It may be simple, but probably better and possibly cheaperthan anything you can make yourself. Then you can turn it into something better by changing the optics. That won't cost anything more than buying the same optics for a home-mad mic.
I can see two reasons for making one youself. Economy isn't among them:
1. for the love of making such a thing - then I have said nothing for it is an excellent motivation;
2. if you want such a special device that you can't really buy it - but then you probably already know more about microsopes than we do...
Agree with every word.
So, now we can do without those condensers?
I think we can both agree that a compound microscope includes an eyepiece and objectives. A condenser is benefical, important and expands the capability of the instrument, but it is not ABSOLUTELY essential - at least for a beginner. Some basic-levels microscopes without condensers are being sold, for students. And there are novel designs for condenser-less microscopes, emplying LED arrays and rings instead.
So I thought that for someone who would like to construct his (seemingly) first microscope, instead of buying it (the more reasonable solution IMO), it is OK to think that a condenser is not a must.