The fact about floppy disks is that they are a magnetic powder embedded onto a plastic base. Most plastics over time degrade. In the case of disks, this means that bits of the powder (which is the material that holds your information) starts to become unreliable. In short it falls off, becomes randomly oriented, and gapping appears. This of course destroys the data.
Recovery firms use lasers and other tools to do a forensic data reconstruction of your disk. They basically read the whole thing, and create a digital duplicate on a drive, then try to patch the gaps. It's not easy work.
From what you say, your disk has passed from this mortal coil. It's not going to be readable by any normal method. And your friends are correct, it will cost a pantsload to use a recovery service (The better part of a grand, if not more) and even then they might not be able to recover it.
Your data is lost. Your best investment is starting on reconstructing it from scratch, or finding others with copies.
And, this goes without saying, and I don't say it to be a wise ass, this is why any important information should be backed up in multiple formats. IT folks have a saying "All drives fail" and it's true. I recently had a pretty big flash drive blank itself for no reasons that I could find. It still works, it still can read and write data, but everything that I had on it *poof* gone. The saving grace was the drive was the backup of the backup. So I just reloaded it.
Sorry for your loss. We all have had it happen... at least once. Usually that cures one of not backing up.
Myriads