Once you've found the money to pay for the construction cost, here are three practical things to check:
Rough surface
Soft, wet surface
Takeoff gradient.
Roughness is tested by driving over it in a laden 4wd or utility at 75/80 km/hr. What I do is use the personal car of the local manager/owner - it focuses their mind wonderfully on the strip condition when they have to drive it in their own vehicle.
Soft, wet surface is tested by driving over it in a zig-zag pattern at very slow speed and looking for wheelruts more than 25mm which indicate soft areas. Maybe give a couple of spots a dig with a crowbar to check that it is not just a hard dry crust over a soft base (absolutely essential if you're in an old lake bed or there are white salty patches around). If in doubt, borrow a 5 tonne truck and drive the runway using that. If it doesn't get bogged, your 2 tonne aircraft shouldn't either.
The takeoff gradient can occasionally be tricky if the ground is generally sloping. You're looking for maximum 5% clear gradient (which is about 3 degrees). I've been caught just the once where a strip approach looked reasonably clear to the naked eye, but the whole landscape was sloping and the actual takeoff gradient was 11%. If the aircraft had ever got off the ground, it would have hit the rising ground further along.
The only way to be sure is to use a small clinometer (costs about US$60), but you can make your own. Got this cute method from Elanora primary school. You will need a drinking straw, a semicircle of cardboard, some tape, a piece of cotton and a weight. Use a protractor to mark the cardboard into degrees from 90 to 0 to 90 with zero at the bottom of the curve. Tape the straw along the straight edge of the semicircle.Tape the cotton to the centre of the straight edge of the semicircle. Attach a weight to the cotton.
