To be very honest here, you really MUST prioritize COMFORT first for headphones. If they are not comfortable to wear for you, then ALL other factors like cost and sound quality go right out the window!
What's the point of having the most amazing headphones in the world, if you can only stand to wear them for 20 minutes?
And, as you know, the most comfortable headphones for ME may be incredibly awkward or uncomfortable on YOU.
So, find ones that are comfortable and within your budget, then start looking at sound quality, style, and build quality.
Open back vs close back: I have only heard 1 pair of open backs, my Senn 598. Open backs are an odd listening experience for the first time user! It really seems to sound more like listening to speakers than headphones (assuming that you have only heard closed-back in the past). On the other hand, closed back seems like the "music is in your head". I own both, use both, like both. It's hard for me to say which I really prefer, they are just different. Closed back has a head start for better bass performance, but my ears tend to sweat a bit more while wearing the closed designs. I probably lean a little more towards preferring the closed backs, but I do really like the audio experience for open backs.
I also own a set of the RBH BT ear buds. I'm not really a huge fan of ear buds, but these are good. If I am being very active, they work better for me vs traditional headphones. And, I love that I can just shove them in my pocket. But, the main reason that I bought these is because our city has a hands-free phone ordnance for driving, and my car is too old for built in BT. It's a $500 fine here for driving with your phone in your hand!