[martin]

I work at Verizon, and the $45 data plan is definitely the way to go. The $25 plan limits you to 10 Mb and it really doesn't take long to blow through that. You could, as advised earlier, try the $45 plan for a couple of months, then downgrade if youre consistently using less that 10mb.
At the store I work at the manager will not let one out the door without the $45 data plan because experience has taught us that once a person starts using the internet functionality they continue to use it and always go over 10 Mb. When that happens, they come into the store wanting credit for overages.
The $29.99 data plan is only for the Q, 5800, 6800 and Centro.

As for the $100/$50 advanced device credit, that has gone away. You now get a $70 rebate and lower initial pricing instead.

Also, as stated earlier, it is best to deal with a direct store rather than an authorized retailer.