In my case I'd have to upgrade all five of my lines (I'm currently on a MSV plan after all) to Unlimited; based on the pricing math and historical data usage it might not be beneficial from a cost standpoint for me to upgrade to Unlimited--as it is I currently pay $185 (factoring in the $10 increase noted in my initial post, but not including taxes and fees) for my MSV 35 GB plan and have never gone over 20 GB despite rollover (which was the cap on my previous MSV plan).
OTOH, if I were to upgrade to Unlimited then the minimum I'd have to pay (again, not including taxes and fees) for five lines is $150/month but that only gets me the barebones Unlimited plan (no Mobile Hotspot, SD (vs. HD) streaming); mid-tier Unlimited is $175 (this gets me Mobile Hotspot but still SD streaming), top-tier is $225 (Hotspot, HD streaming, live/On-demand TV, choose one premium music or movie service)--all three plans require Autopay and paperless billing to qualify for those prices, otherwise it's an additional $50/month for the lower two tiers, $20/month for the top-tier. However, if I were able to get my 25% FAN discount applied to the top tier plan then it would be worth it for me to switch...guess I'll go ask AT&T about that.