can i jump in? i'm not professional, but i love oil paints!
i started with a cheapo box of 12 tubes for $10, used the cheapest brushes around, & painted on board, which i primed with leftover wall paint. by the time you empty a tube, you know whether or not you like oil paints & you can replace the colours you use the most with better quality ones. same with the brushes! and there's non stinky solvent to clean brushes in now, although turpentine is still much cheaper!