First, welcome to the forums!
As far as a “back-up” throw goes, you really have tons of options. I see that you are worried about being disappointed with other yo-yos, and sometimes that will just happen. However, each time that I have thrown a yo-yo around and decided that it’s not for me, it has always come down to the same thing: I just didn’t like the way it felt on my hand or on the string. There aren’t very many yo-yos on the market today that don’t perform, you should see what [noembed]Brett can do[/noembed] with a Lyn Fury. It’s all going to come down to your preferences.
Since the M1 was your first yo-yo, I would imagine that you don’t really know what you’re going to prefer. With that in mind, here are some low cost throws that are for the most part unresponsive out of the box. In my experience, they are all amazing players.
Under $20
YYF DIE-NASTY super smooth, AWESOME value
YYJ Lyn Fury most come responsive, but they can be set up unresponsive
Under $30
YYJ Legacy My Favorite. Plastic. Ever.
YYF Plastic Grind Machine v2 hubstacks are FUN
YYF Counter Attack truly a very impressive yo-yo