Best deals/approach to adding a 3rd line
My wife and I are currently on a family plan. Least number of minutes shared. We started out with two 3GS units and I upgraded mine to an iPhone 4 when it came out. We also started out on the least number of text message plan (because we only texted eachother), but my wife became a texting addict and I got dinged a few times with overage charges, so I begrudingly bumped up to the next tier in text messaging (and they dropped the cheapo plan so I can't switch back). For now, we're both still on unlimited data but my wife only uses about 200MB while I use close to 2GB (not even sure how - I don't video stream, but I do use Pandora and sometimes stream podcasts when driving).
Anyways...so I've still got my old iPhone 3GS lying around unused. We started my 12-year-old daughter out with a cheap pay-as-you-go phone last year and she miraculously didn't lose it (well, she left it over a friend's house a couple of times, but it was always recovered). Now that she's a bit older she's been nagging me for the old 3GS, but I'm dreading committing to the added extra cost per month. But I just priced it out and it looks like it may not be too bad. We get a corp discount on certain parts of our family plan, and when I priced it out online, it looks like it will cost $42/month total ($10 add-a-line, $22 discounted for 2GB data plan, and $10 for 2000 messages). Whereas I'm probably spending about $25 every 30-60 days to add another $25 to her pay-as-you-go phone.
When pricing things out, I see that AT&T is offering a refurb iPhone 4 for $99, so I'm thinking of getting one of those and either giving it to my wife and having my daughter take one of the 3GS units, or letting my daughter start right out with the iPhone 4 (and upgrading my wife separately - hopefully using her upgrade to get me an iPhone 5 around September and then giving her my iPhone 4).
In any case, a few questions:
1) Anyone here get a refurb iPhone 4 from AT&T? Are these generally in great shape?
2) If I give the iPhone 4 to my wife, what sort of hassle will I have to deal with so that my wife keeps her current phone number and data plan? Should/Can I bring my wife's 3GS and the new iPhone 4 into an AT&T store and have them re-configure the SIM cards, or am I better off cutting my wife's 3GS SIM card down to fit the 4 and just having the AT&T store transfer the new line (with, presumably, a new SIM) to the old 3GS?
3) Is there any way for me to have this new line set up so that when she uses up all of her data and/or SMS messages that it shuts her out, rather than automatically tacking on an add-on package for the overage? I believe that AT&T offers this as an added cost "feature", but I'm hoping for some free way of handling this.
4) I was also considering trying to pair the old 3GS with a pay-as-you-go plan (and there's a recent thread in the forums here about doing that), but it sounds like that would be a hassle and would be more expensive than the $42/month I'd be looking at. That said, I'm curious if there's a way to just add $25 worth of pay-as-you-go dollars to a 3GS and locking her out of data usage altogether (except when on WiFi).
Any other thoughts/advice would also be appreciated.