Gravel may be suitable for your own driveway needs, but potential buyers may not like gravel as much as you do. Depending on the climate in your area, gravel can be difficult to maintain in certain weather conditions. Gravel can become muddy during rainy times and is more difficult to plow or shovel. Gravel strip driveways often develop deep ruts which are also undesirable to potential buyers.
Your home's value is partially determined by the average price of similar homes in the neighborhood. For instance, if yours is the only home without a paved driveway, it may be perceived as worth less than surrounding homes. Likewise, if your home has a paved or brick driveway that has recently been installed, it will be perceived as more desirable than surrounding properties with gravel driveways or driveways in need of work.
Paving a driveway will generally increase the value of your home at least as much as the cost of the driveway itself. The value will increase even more depending on neighborhood, the aesthetics of the driveway and the width of a driveway. A wide driveway that fits two vehicles is going to be of more value than one which is barely wide enough to fit a compact car, for instance. The value has a lot to do with perceived value and the needs of potential buyers. It may be worthwhile to spring for some extras, such as adding a walkway from the driveway to a back door or patio, as it will increase the appeal of the property.
Common, basic maintenance will increase the curb appeal and therefore the sellability of your home. If your paved driveway is cracked, uneven or is otherwise in a state of disrepair, get it fixed. For an asphalt driveway, resurface the entire driveway or at least sealing any cracks before putting your home on the market. At very least, pull weeds and grass growing in cracks and around the driveway in general.