Transcoding from one lossy format to another decreases the file quality. Converting to ALAC would not decrease the quality -- quality would remain lossy -- but

Transcoding from one lossy format to another decreases the file quality. Converting to ALAC would not decrease the quality -- quality would remain lossy -- but would drastically increase the file SIZE. DJ online music stores such as beatport and stompy sell WAV or FLAC files. I really don't understand why iTunes and Amazon don't sell lossless. The bandwidth is there, the demand is there, I guess FLAC isn't supported by major players but at the very least have iTunes sell ALAC... Please.