It's not going to give you a very precise result, there is nothing in between alkaline and highly acidic even assuming it is accurate (no soil amount is given) and how alkaline is "alkaline"? It's also not as simple as adding lime or sulfur to change pH either way, you need to know how much to apply which depends on knowing an accurate pH and your soil type. You'd probably get as close an idea of your pH by looking at the plants that grow well for you, or don't. If you can grow rhododendrons, azaleas and blueberries well, then your soil is pretty acidic, for example. If certain iron chlorosis prone plants get yellow between the leaf veins then chances are the pH is too high for them. If everything you want to grow is doing just fine, no need to tweak the pH.
Another option besides buying a soil test kit for home is to take a soil sample to your extension office for professional testing. Looking at Clemson University, SC, for example, it costs $3 for a simple pH test, and $6 to test pH, nutrients and to give fertilizer and pH adjustment recommendations, according to their website.
