That doesn't make any sense.
Cydia will not let you download any package over carrier data that's 10mb or higher?
My wifi and 3G speeds are about the same and I can't download 10 mb + packages on 3G. Seems to be by design? Anyway around this?
Correct me if I'm wrong but are you trying to download over-10MB files over 3G?
If that's the case and you have not installed any kind of restrictor before. It's pretty much because of your 3G network carrier.
Maybe something to do with the particular repos server or dns settings.
I noticed before when connected on a very fast wifi connection it would take forever to update a cydia package. And once I turned off wifi and did it over LTE it would be done in seconds.