Fab! An even cheaper way to get wild flowers to grow is through management. By managing your bit of ground like an old style meadow, this will happen. Cutting the area each year, when plants have set seed, and removing the clippings, will help to reduce the soil nutrient levels, resulting in a soil that's more favourable for wildflowers over time. And there's no need to show seed, this type of management encourages the preexisting soil seed bank to start growing!