Rechargeable batteries and battery chargers can be a wise decision for many uses. The initial price tag is higher, but the overall savings are very easy to add up. A rechargeable battery is on average, good for 700 recycles. Higher capacities and low self-discharge technology is increasing the time between charges and further improving the savings. High cycle rechargeable batteries such as Eneloop can be recharged over 2000 times.
It's important to remember that it's not really possible to compare the performance of rechargeable batteries with that of alkaline. It's highly variable based on the amount of current drawn, and can be hugely different between devices. Also, please don't forget that rechargeable batteries do not last forever and the quality of storage, the type of recharge cycles, and quality of the charger used can have a huge impact.