What is the chance that my portable Magellan Crossover GPS unit can be repaired or work again?

The unit has been used very little, even though it's about four years old. It was working fine on a cross-country trip last month when it stopped functioning in central Texas. Now it won't go past the Warning/Disclaimer page when you turn on the power. It does this when using the power adapter plugged into the cigarette lighter, the built-in battery after it's been fully charged, or the A/C power adapter indoors. I'm guessing that it's toast and that it would cost almost as much to repair the unit than it would to buy a new one. I'm thinking of buying an iPhone anyway, which has a GPS feature. I know it's not the best GPS available, but it will probably be sufficient for my needs. I welcome all answers or suggestions.