Hi, I am new to the forum, but i totally agree with you on this. However my FM and Tietze Syndrome (similar to costocondritis) have me very sluggish, since even very minimal movement can cause me pain. We had our new beds delivered this weekend and as I was helping move the twin beds by sliding them down the room standing up lengthwise. The next hour I was in immense pain and stopped in my tracks unable to breathe without pain. It was not fun, and my husband was very worried, but I pushed through it since I knew we had to go shopping for sheets which I did with a smile on my face so my kids would not worry. I hate it when they worry, that is the worst.
The Tietze, is painful just sitting, since almost all of my ribs are painfully swollen at the connection to the sternum. At first I thought I was having a heart attack, shortness of breath, tightness in my chest, severe pain and spasms which were scary since it really hurt all over my chest. After two trips to the emergency room, the first doctor gave me muscle relaxors and a z pack and called it "an infection in my plura" the next time which was about 3 years later, they could not find anything wrong with my heart, when I kept telling them it was the plura, and they never even checked it, which really irritated me. But thankfully it wasn't my heart, but that was the only thing they checked. They said if the pain still bothers me to go see my doctor, well she wasn't available for 2 more weeks, so I asked to see someone else, and I had an appt the next day and he was great. He listened, he was attentive, and he did several tests, and then figured out by physical examination that it was Tietze. So I was given another muscle relaxer and was told to take it easy and try and figure out what I was doing that caused the pain (before dx of FM). Pain kept on, I was lying in bed not moving for two days and the pain was so bad everywhere I doubled over crying. So I called my reg doctor, she got me in and wanted to run tests, not ever discussing the Tietze, of course since she didn't diagnos it then she wasn't sure that was what it was, but she agreed there was pain in all the ribs. So finally when every test came back normal, my life as one big medical mystery.... All along I was still in pain and getting worse, like nothing I did helped. So she referred me to a physical pain and rehab doctor, who could't see me for almost a month, so I waited, in pain. This was my November, then almost Christmas I was DX with FM, all the things I have delt with and there it was a name, finally. But the Tietze, is still bad, and both doctors still do not confirm, as the other doctor did, that it is Tietze and not just the FM causing me pain... Why there then, and why is it not going away. I do laundry and I suffer, this is not fun, I can not exercise with my upper body without sufferring the consequences.
All of this just to discuss your symptoms or issues with Costo, I do not wish this on anyone, Tietze or Costo but needless to say, I hope you get well and find releif with it. I plan to do water aerobics, just hard to get to the pool when it's so cold, can't wait till summer. I am off to the pain doctor for Lidocaine shots today, in my trigger spots, been having severe headaches and back pain, not sure if those will be the only a few spots for the shots, but I plan to ask about the Tietze today too. Well I am back from the doctor, was not able to post earlier(some computer issue)and the doctor got rude and defensive with me, saying "you don't have Tietze Syndrome, that it only affects one rib, not more than one". Well I disagreed but decided to hold my tongue, I should have had her prove it to me. Anyway everything I read on it, and the doctor that diagnosed me agrees, it's all the ribs and it can be very painful. I am going to find a different doctor. Had the shots today too, which hurt, I probably should have walked out when she told me flat out that " No you don't have it, quite rudley infact"
Hope your doing well, take care and smile, it does help the pain at least some.. 
Have a great day.
CiCi