They will sell eventually, the composiums first followed by the hole, likely.
There is a lot of money to be made, but patience is required to do so since you're waiting for someone to require your offerings for a level upgrade. For example, the composium hole will only be bought by someone building the level 52 s/s weapon... someone who doesn't want to bother making it himself. There are only 16 level 51 characters at the moment. How many are active, how many use s/s weapons, and how many don't have the mana/patience to build their own composium hole? In other words, it's a pretty small demographic. Composiums are in far greater demand. To keep your income flowing, though, you'll probably want to start diversifying once you have enough money to do so.
Take a look at extra houseparts as a possible upgrade for your composiums (which I presume you are digging up the ingredients for). They are often way over-priced. They sell quickly at 100k and slowly at 120k. You can make [url=
http://forum.flyordie.com/thread.jsp?forum=13&thread=30394
]quite a bit of cash
/url] through them if you're willing to do the repetitve builds.
Sandy