First of all, you can use APT to install older versions. Second, you can always make up a case where the packages in the repos don't do 100% what you desire (maybe you want some different build options, or dependency versions, etc). The packages in the repos are designed to cover most cases, and to work together with the other packages on your system. So I have to ask: are you SURE you need something the packages don't give you? If so, then you have agreed to take on the extra work to get what you want, and it's understood that it may/may not be trivial. This applies to any software.
Even so, APT does help you quite a bit with build dependencies, so whatever non-standard thing you've decided to do, you can still do it with (hopefully) not too much work. Feel free to ask me about any specific thing you're having trouble with.
Even so, APT does help you quite a bit with build dependencies, so whatever non-standard thing you've decided to do, you can still do it with (hopefully) not too much work. Feel free to ask me about any specific thing you're having trouble with.