That’s the bulk of it. There might be other costs as well, but the commission is the biggest (assuming there aren’t repairs that are needed). Here’s a more detailed answer: How Much Does It Cost To Sell A House? | Bankrate
Honestly, yes it will. It is easier to sell (and get higher bids) if buyers can picture themselves living in your place, and that’s harder when it’s filled with your stuff. But the harder question is if it will hurt you more than the cost and hassle of staging it. That will depend on your condo and the local market. Are you going to be competing with other nearby units that are nicely staged, or is everything selling fast no matter what? These are the things that a local realtor can really help you decide,
There’s no great solution to this. I think this question comes up fairly often here. I haven’t looked through these threads in detail, but here are three that came up in a quick search:
How to sell and buy a house at the same time?
Advice on SECOND time home buying
Sell our house first, or buy a different house first?