Hmm, given the huge limitations here, I'll say try the Koss KTX Pros. Supraaural, not too hateful, $20 or less. Try Rat Shack, where they are called the Pro 35s. (Normal list at the Shack is $30, but they are on sale every other week (literallly!) for $20. You can also order em from Amazon or Koss. You will never listen to em again after you get better phones, but they will tide you over.
Another option, Senn MX500s are bigger than the average earbud and tend to stay in even pretty big ears well, They go for $18, and can be found in Virgin Megastores, and from headphone.com. (Maybe Rat Shacks in your area also...) Due to their nice sound and portability, you'll probably use em even after the JVCs arrive.
Final option: get the Koss Plugs and modify em. Get em from the Shack (under their own brand name) for $20, or from Kmart. Bestbuy sells em for $25, which is too much. The mod is simple, cheap and even kind of fun. Look over in Headwize for info....Let me know if you can't find details and I'll scout em up. The Plug is a set of cheapo canal phones, and sounds pretty OK with the mod, though rotten without it. Again, when you get better phones, these'll go in a drawer somewhere. The MX500s are your only bet if you want interim phones that may be good enough to coexist with other more expensive cans...
hang in there!!