With yoyos, it's a lot of fun. I collect what I collect to THROW. I am not just buying stuff so it can look pretty in the box or on the shelf. Everything I have I throw. Some more than others, but everything gets used.
Yeah, if I can get the box or "MINT", that's great. I like them to be as nice as possible off the BST. But, sometimes a few nicks and scratches can be fine.
My preferences are for full sized/nearly over-sized that are 67 grams to 69 grams. I also have stuff smaller, narrower, heaver, lighter. different shapes, weights, and whatever. Metal, plastic, metal and plastic, and even a wood looper. I have yoyos for all the 5 major play styles, so I can do what I would like to when I would like to. Want to try looping? I gots loopers. 3a? OK, mybe not ready for that, but I do have some identical string trick yoyos. 4A? Got a bunch. 5A? Got some counterweights. I like variety, I like to mix it up, I like to get comfortable with something and then force that comfort zone to fall apart. I mean, for me, why buy it if I'm not going to use it? Seems kinda silly to me. But that's how I look at things. I am throwing my Wooly Marmot and Campfire way more now that I have a yoyo case and they don't need to sit mint in their mint boxes. Yes, they are pretty 28 stories colorways, but what joy is there with a yoyo that you don't use?
The big things are:
Don't spend more than you can afford.
Have a place to keep everything. Sometimes this means buying cases and the like.
Whatever you do, do start slow. Budget. Be smart. Have goals and work towards them.
When I started, I got a Reflex and an Imperial. I figure if this whole yoyo thing didn't work out, that was enough to figure it out. Obviously, it did. DM2 was my next purchase and the rest has been a lot of fun. It may sound negative, but in todays' "high priced toy" marketplace, you have to plan for assumed failure as the primary result. It can always change into "success". Minimize start up costs to reduce losses. If it works out, then those initial purchases may still be losses because you're replacing it, but they won't be true losses because you can still enjoy them.
As far as general yoyo tips:
Practice. But, when it stops being fun, stop. Serious. This is supposed to be fun. It shouldn't be "work". Don't get discouraged. If you need help, ASK for it. If there are meetings and clubs near you, GO!! Trust me, many of these people want to share what they know and will see what you're doing and help you do it right or better.
If you get frustrated, just stop. Walk away, take a break. Calm down, then come back.