It's odd that most of us just grab a pack of single use batteries every time we need AA or AAA batteries because they are three times cheaper than similar rechargeable batteries. Whilst its true that rechargable batteries do not have 100% the same usage characteristics (for example you can't charge them and then only use them 5 years later as they lose more power whilst not in use) but generally they can be used for many applications and are ideally suited for high drain devices. But I have been using them in a radio, a weight scale, etc quite successfully.
Generally rechargeable batteries could be good for 500 to 1000 recharges if not exposed to extreme temperatures, ultra-fast charging, etc. So you also want to ensure that they are charged with a quality charger intended for that battery chemistry type (NiCd, NiMh, Li-ion, etc). So yes an initial outlay on getting a really good charger (one to handle many battery chemistry types, refreshing, and more advanced options) will also cost more. But why skimp on the initial outlay if so much can be saved over the longer term.
I compared the prices at Takealot.com for four-pack Duracell Ultra AA 2850mAh at R59 with Duracell AA Rechargeable 2500mAh at R179 (US$1=R14,50). Yes with good care and use the rechargeables could get 500 or more reuses but I think it still roughly illustrates the point I'm trying to make. The same goes for buying single-use batteries in bulk (or cheaper brands) as the cost per battery does come down but it will not be 50x cheaper or less environmental waste.
We have become such a disposable single-use society (think of cartridge vs safety razors as well) and it is costing us dearly in terms of cash as well as the environment. Companies are making a lot of money out of our single use habits and unwillingness to invest up front.