Is this a reason to get mad?

My Galaxy recently stopped working so we used insurance to buy a new one for $125. I was doing some looking on eBay and I realized I could sell my phone for like $300 because it's new and use that money to buy a used iPhone 6. When I brought up my plan to my mom she didn't approve, but still said I could do it anyway. So I asked my dad if I could use his eBay account and he flipped out. He started ranting about me always needing something and complaining about money. I don't understand why when I'm selling the phone for 2x more than we bought it for and I'm not asking for his money. Is this a reason to be mad or is he just being unreasonable?

That is a reason to get mad

answer my question?

Apparently, you and your dad have two different versions of what has been going on, not unusual. From your viewpoint, its "unreasonable", but not from his. If your mom has an ebay account, use hers instead; or, if you are old enough, get your own. Or, find a friend who will let you use theirs. Leave your dad out of this one, he's clearly sore about this and probably other stuff and won't say yes, no matter what. You two need to clear up whatever the disagreement is, sit down with him some time, calmly, and ask how you can make things better. Ask him if he will listen to your complaints as well.

You don't know you could get $300, just because someone asks that doesn't mean they are actually getting that.

I don't believe so Dr.Stephanie can you help me

"and use that money to buy a used iPhone 6"

Which will have no insurance on it at all. When you buy a used item there's often no warranty. If it stops working a month later you are just out the money.

And did you stop to think about your fathers concerns? Teens always seem to think they need the latest/greatest gadget/shoes/whatever. Maybe his real concern is that you are getting spoiled and will think you are owed something for the rest of your life.