Hello,
I am Actionscript 3.0 programmer working in Flash, Flex and Adobe Air. Please take a look at my feedback. All my works are exclusively in AS3.
Regarding this project, the current mixture you have referred is in AS3. I have earlier done mixing and recording application in AS3. If you want the mixer excluding "Save as Link" and "Export to file", then surely its about 100$ job. But if you need to mix it at the byte level, then this is beyond 100$ job.
Let me know what do you think.
Regards