What are the cheapest options to fix the paint on my hood?

The only real solution to peeling clear is to strip the panel back to primer and repaint it because it shows the clear is going to fail over the entire panel over time. Buffing and such won't do anything because what you are seeing is the clear coat layer lifting off and the air getting under it. Now if you just want to make it less visible you could do something that can help but it won't really stop the problem, just hides it. Go to a place like Eastwood that sells automotive two stage clear in spray cans. Search for Eastwood 2K DuraSpray Clear High Gloss or 2 stage gloss clear spray cans. Some local paint shops carry similar paints.
First wash the car, then wipe it down with wax and grease remover. Go gently on the areas the clear is already gone, the color coats are very thin, and you can rub right through it. Mask off the other panels around the hood (a quick way is to open the hood and lay the paper down then close the hood, you want to protect the fender tops, glass and such from overspray. Now take an air hose and use high pressure air to blow the peeling clear off the panel. Sort of like you would use a leaf blower. This will blow off much more than you think as some won't have lifted off yet. Now don't touch the surface with your hands, get all of the areas prepped, now mix the clear coat per directions, Spray on a light mist coat and then a heavier coat. Let it flash in the direction and give it another coat. Keep going until you get a few coats built up. Now let it cure. If it looks good, then you can leave it. If it's a bit fuzzy you can take some 2000 grit wet or dry and wet the areas down and sand off the roughness, just keep in mind it's a thin clear coat. Now use your buffer on it. This won't make it look like new, but it will at least remove most of the bad clear and protect the color coat underneath from UV and other damage.