To POS or not to POS?

So the title says it all -I'm in doubt.
One one hand I want a POS to get an easier access to assembly lines. On the other hand I don't know if I need it yet.

The biggest point for having my own POS at the moment is the time I have to wait for a public line to be free. Here a POS could help me expand my "one man empire" and hopefully make me make more ISK than I do now.
- the price of a POS is not my main concern right now as I could always do a ton of mining to get the ISK needed is I set my mind on it... not that my bank is empty at all.

What makes me go "hmm" is the fact that I maybe should wait till I have a certain amount of SP in industry to get my ISK worth in a POS. Only I don't know what this amount would be.

So is there a given point that makes a more valid time for a POS?

As it is my prodcution is mainly frigates, ammo and other small things like this. But I want to get into more production/research as I like the "crafting" system in EVE.
I don't own a ton of BPOs yet, but I buy some from time to time. At the moment I might have 20-25 I guess.
- strange how I felt stoked when I bought my first BPO (Navitas).

In some way it feels like the next step to get a POS - but it feels like a huge step (more to me than EVE-kind).

The last few days I've read a few blog posts and guides about POS but they all seem to be written in "old player language" making it not so easy to read as a rather new player. So I might be setting up a challenge I can't overcome.

So much EVE, so many options - so much to learn.