This issue can be overcome if you can establish a legal, recorded easement to the property. This can be done if one of the neighbors is willing to allow you access through their property – to yours. In many cases, a neighbor shouldn't be expected to do this for free, you'll have to give them a reason to help you (usually in the form of money). Again, this isn't an impossible issue to overcome, but it is definitely something you'll want to be aware of before you purchase.
Market for Land is Less Active – The market for existing homes is almost always more vibrant than the land market. There simply are fewer numbers of buyers for vacant land than consumers looking for homes. Start marketing a new home listing and a new lot listing when both are desirable and priced well, and you generally can expect fewer contacts about the new lot listing.