Expected device lifetime
With the average tablet costing between $250 and $650 it is a worthwhile question to ask yourself how long you expect a tablet to last in field. With PC’s many market research companies use a 3 to 4 year depreciation scheme. For tablets and smart phones you might consider reducing this to 2 years. Not only because tablets are cheaper, but also because the specs are changing so quickly a 2 year old tablet might look outdated after this period.
Especially when you consider buying a device that is not running on the latest Android OS, do take into account that life span will be shorter.
If looking outdated is not a problem, you might go the other direction and look for a durable device that will last 4 years or even more. In that case consider the more expensive ruggedized type of tablets and smart phones that are used at construction sites. These devices are shock proof, water proof, dust proof, can be used in direct sunlight and come with replaceable batteries. But they also come with a much higher price tag that can easily exceed $1,000.
A question you need to ask yourself is whether you want to insure your devices. Annual insurance costs are often around 20% of the value of the device. This means that on a company level you will need to claim 20% of the machines in a given year as damaged/broken/lost to break-even. When you have only a limited number of devices it is often a smart idea to have insurance as 1 or 2 broken devices can have a big impact on the total cost of ownership, but for a larger field force it is often cheaper to repair or replace broken devices at your own expense than to have the devices insured.
Many manufacturers offer a standard one-year warranty on their products. In many cases it is possible to buy an additional one-year warranty. Before you consider this offer, check your local legislation on warranty as several countries require manufacturers to give a two-year warranty by law. If you do not have two-year warranty by law, the arguments for deciding about extended warranty are the same as for insurance.