Well, if you average at over 2 minutes, speedcubes are not your priority. Buy a storebought, heck, buy a few storeboughts. By the time you start getting better times, you will have broken it in (Make sure you lubricate the cube, it will speed up breaking the cube in). After 2 years, my storebought cuts corners and turns better than any DIY I could imagine, and I perform 0 maintainence, other than the occasional lubrication...
And start using finger tricks if you haven't already. Using fingers instead of full hands will decrease your times TREMENDOUSLY. It's the first step in cubing.
Heck, using the beginner's method, I've accomplished 26.72 seconds with my storebought cube!
This.
Get a speedcube when your f2l is like say 10-15s.
I don't see the point in waiting to purchase a decent cube. I'm new to speebcubing myself, but my rubik's storebought is just so tight it's annoying. For example, doing a double flip just takes more effort than it should do. How can you practice using finger tricks if your cube is way too tight and doesn't allow it properly?
I'm using it for quite a while now and I don't think it will ever become a beast, maybe it will improve a bit (after some more breaking in), but I don't expect anything shocking tbh.
You advise someone to break in a storebought for over 2 years, so that it
then becomes better than a DIY, while there are DIY's which are great out of the box?
Moreover you advise one to buy
several storeboughts? Well, then I'd advise one to spend your money on several different cubes, buying some DIY's (different types) and perhaps even a storebought (probably you already would have one as a beginner) and then see which cube suits you best. It might be the storebought, but it's all personal preference right? So why not try different types and see which type you like most? Why wait two years to do that?
Just my 2 cents (even though I'm a beginner)