1tb per month per user bandwidth on box.com would be totally fine for me.
AFTER I MIGRATE.
Fingers crossed that is what happens for me. Quite worried that I'll fail, but all I need is 135tb migration+the 3tb per month they claim is fair. That'd be plenty for me, forever.
It's a shame these companies don't consider migration, and their service reps cannot comment on such matters when asked about them.
edit: The part that scares me is that I do NOT have that email, yet I haven't been able to make uploads normally at all this afternoon, despite them working flawlessly yesterday 
Maybe they meant to email me but the email got lost?
edit2: It looks like their bandwidth limiter is wasting a gigantic amount of bandwidth!!!! omg.... files are getting to 100% data transfered to box.com THEN being error'd out without being copied... in other words... their bandwidth limit cannot limit bandwidth AT ALL, if anything it just forces rclone into an infinite loop that wastes extra bandwidth?!
edit3: See? huge waste of bandwidth to only throttle files AFTER allowing 100% of a transfer
edit4: box.com isn't even reliably giving out 429 errors, it's failing uploads at 100% without giving an error which means rclone --retries=0 won't even help them because retries are happening without being counted by rclone as retries, this is the worst bandwidth throttling code I've ever imagined, it makes me think they developed it this august and rushed it into service?
edit5: So for everyone 429 error people see in their log there are tons of unmentioned file upload resets happening from box.com's bandwidth throttler, which... as a result... is automatically INCREASING bandwidth usage from anyone who is using rclone and isn't studying the log's with an extremely detailed fine tooth comb.. so this is likely going to backfire in terms of box.com's own goals... I was seeing about a 50% success rate in terms of uploaded files to 429 errors, but for all I know that's more like a 5% success rate due to these hidden file transfer resets.
edit6: I'd estimate this afternoon while I was paying attention I uploaded around 40gb of files to box.com while wasting 300-400gb of bandwidth on 429 error and silent restarts... so their bandwidth limiter is.... not at all limiting bandwidth and if anything is increasing it by 1000%.... but hey tomorrow is a new month? So maybe they'll ease off tomorrow because people will be at 0bandwidth for the month?
edit7: okay let's assume box.com isn't incompetent. What is this bandwidth limiter doing? This bandwidth limiter that is actually increasing bandwidth usage? It's actually limiting harddrive space required. But fully allowing uploads then refusing to allow the file onto the harddrive. This actually scares me more. Because if this is true, they're not low on bandwidth, that part would be a bit of a lie, they're almost out of harddrive storage instead, but since they claiming they have unlimited harddrive storage, they're claiming it's fair usage bandwidth consumption that's the issue.
This is very bad for me personally, because 3TB per month bandwidth would actually be fine for me long term. UNLESS the real issue is that they're not harshing enforcing bandwidth limits due to being nearly out of harddrive storage
So fingers crossed that there is just a bug in their bandwidth throttler code (which actually only throttles storage space requirements.)