Take this from someone who knows....you can put pens up for auction on eBay and they will sell for less than the kits to make them. I have started pens at $.99 and got no bids....
Additionally, whether we like it or not...there are a lot of folks out there who make pens strictly for a hobby. If they sell a pen and cover the cost of the kit and blank they are happier than a pig in mud. Their pleasure is in turning the pen, not making the sale.
That doesn't make it any harder for the rest of us to sell pens....trust me, people who are paying $5.00 for a hand turned pen aren't going to buy one for $10.00 or $20.00 or $50.00. If nobody will sell them a pen for $5.00 they won't buy one at all.
EDIT. One other point...if one has a couple of hundred pens sitting around the house there can be a lot of money tied down....That money isn't doing one any good at all, so if one make pens for a hobby rather than a business it makes perfect sense to sell them for what he/she can get out of them even if it is less than what was paid for the parts. It gives them some money to continue to enjoy their hobby. Those of us who sell or want to sell our pens as a business and turn a profit, have no right to expect those who do not to do anything at all to support our prices.