Why do cell carriers offer new phones to new customers, but refuse to offer the same phones to older

This is called subsidizing your Cost of Aquisition. Yikes. The deal is that the cell phone companies are actually investing in the customer to make money on the service, not the phone. They lose up to $200-300 per phone expecting to make that back over the life of the contract. Typically wireless companies require the subscriber to stay with the company for 9-15 months for them to make money. That is why there is a penatly of $150-200 if you cancel the contract, to get this subsidy back, or at least some of it. Cost of Aquistition is the key financial for people looking to invest in wireless companies btw. If they are high, likely they are not making any money. Nextel is the highest with local small carriers like MetroPCS and Cricket being the smallest.

Some companies sell them at reduced costs if you renew your contract again with them. They are re-investing in you.

Sometimes you can get the same phone on eBay for less than what you see at the stores, so check there.

Because they already have you as a customer, and If you leave before your contract is up, most of them have a penalty that they want you to pay. Wait and see when your contract is up they will offer you a new phone for free or @ a low cost.

New customers mean more money for them and less for other cell phone companies. You can pay regular price for a new phone, of course. A lot of companies are changing that now. sprint offers you a $150 rebate after you have had your contract for 18 months, I think cingular does something similar. almost all companies actually have contract on the phone line not the plan so once your contract ends you can usually choose to simply start a new contract and still qualify for most of the same discounts that new customers get. even though you are a current customer you are a "new" contract.