Well usually packages already come with information on what they are getting, if they want to get a bit more they can always ask to see if they get more for the price they are given for more resources.
I have a perfect example of that.. This week a member at WHT contacted me asking various questions about becoming a VPS provider. Many people would've just said "you need to figure that out yourself". And although it was helping the competition, I only spent 1 hour+ guiding this guy through his options, my suggestions, etc.
Long story short. He's hired me to design/develop his site & help setup shop. A project that'll keep me quite busy the entire week, all for an hour of "just giving back".
I would have to agree, when someone looking for a hositng plan on reseller or w/e they usually check out the plan and see if they want that much and they make their decisions based on such plans/contracts if any.
On my website you don't need limits, because you register and earn an free portal to sell all products offered, with cheap prices (http://reseller.regbet a.org/), REGISTER for FREE, and pay only when a customer bought your products