So, if the song costs 35 robux for me, do I still get to set the price? Or is that the price people have to pay to get the song?

Most experienced players probably went bankrupt several times before they succeeded. Another key aspect is time. Most users played for a long time, and their work has paid off.

If you have a product that people really like of course that's going to happen. You have to get a 1000 calls a week or month to make ANY money...

You either do not have Builders club or it is a ROBLOX glitch. Email ROBLOX if it is a glitch. If not, buy Builders club.

This is to compensate for the money the seller lost dealing with a return. Some sellers offer free returns and some don't.

Yes, it costs Robux to upload music, and the cost of the upload depends of how long the file is. Longer files naturally cost more Robux.