10-100mb. Average mostly 20-50.
Might send a couple a week.
The data used should be the files size plus a few extra megabytes. So if you upload two 30MB files it will probably use around 64MB. That is .064GB.
Ahh. Looks like that would burn through 5 gigs quickly. Or even the att 6 gigs.
Not really, even on the higher end of what you said it wouldn't use that much. Let's go with uploading 4 files a week at 50MB each:
4 x 50MB = 200MB. Add 20MB as extra data = 220MB.
220MB x 4 weeks = 880MB (or 0.88GB). That's not even 1GB in a month and you can use 5GB a month.