In general, you will get a better harp for more money. I swear by Hohner Special 20's. They're around $22-25. Haven't bought a new one is a while.
Don't clean harps. Brush your teeth before you play. Anything you blow in can be sucked out, like food which can become moldy and/or can choke you.
I like plastic combs over wood. Richer sound. The Marine Bands seem to bring on cold sores. I do like Blues Harps. These are all Hohner by the way. I also like Lee Oscars. A lot of people like Huang and Suzuki. I don't. Just don't like the sound.
For a good harp, you don't have to spend more than $25. If you're new, go to Golden Corral and buy a $5 harp. You can get enough sound to decide whether you want to invest more. Long ago, I bought a Meisterklasse, also a Hohner. $65. Looked really cool. All metal and chrome lookin'. Does not sound nearly as good as a Special 20. My second choice are Pro Harps. Again, Hohner. A little more expensive but not by much. Much tighter and harder to play but have a good sound, IMO.