Wood carving was my previous hobby before I discovered airplanes. Invest in a black arkansas stone (hard) and make you a leather strop from an old belt, impregnate with white rough and you are in business, with a little practice. Wood carving chisels have to be RAZOR sharp, the softer the wood, the sharper they need to be. With a little practice, you won't be buying as many blades.
I generally use new ones for covering, sharpen them and use them for building. But one on my sharpened blades is a lot sharper than the ones you buy in bulk.
The leather strop needs to be undyed leather-you may have to go to Tandy leather and buy a piece of scrap leather, use the smooth side for stropping, have one that is treated with white rough and one without for that really sharp edge. I glue mine on a scrap piece of wood, it only needs to be about 1" wide by 4-6" long.