Having a rare skill means that a small increase in demand may translate to a large increase in the the rate your work is valued at, the rate you can charge. If so, focussing on that specialism should lead to greater profits, right? Maybe it can, but there are other forces at play. To demonstrate this, here is the story of a (fictional) thatcher and his business. Disclaimer: I've never been involved in the thatching business, but I've seen a roof thatched slowly, day by day. And believe me, it takes a long time.
The Story of the Thatcher and the Cottage-Owner
The thatcher lives in the countryside. He doesn't spend all his time thatching, in fact, most of his work is joinery for a local farm. But his own house is thatched, and he has kept his thatching skills fresh.
The houses nearby now mainly have tiled rooves, the mark of industrialisation increasingly stamped over the houses. But one cottage at least still has a thatched roof, and it inevitably needs repair from time to time. The cottage-owner has not lived there all his life, and is certaintly no expert on thatching.
One day, a storm damages the roof of the cottage: part of the surface is blow off, and some parts look susceptible to rain. The cottage-owner realises he needs his roof fixed, and goes out looking for someone to help. The first people he finds are tilers: tilers are plentiful and local in this landscape.
The first tiler replies: "We can't fix a thatched roof. We'd have to tile this for you. We'd have to start from scratch, and it will cost a lot of money." The cottage-owner goes to find another.
The second tiler replies: "Sorry, this roof is thatched. We can remove the thatching and tile it, but it will cost a lot of money." The cottage-owner goes off again.The next person the cottage-owner stumbles across is our thatcher. The thatcher looks at the roof and says, "Yes, I see the surface damage." He investigates a bit further: "Let me look inside … ah, some damage from rodents." At this point he uses his own judgment to conclude that he has investigated the situation to an appropriate level, and presents his findings: "It will not be easy to fix, but I have the skills, and this is my day rate. It is moderate, if not cheap." The cottage-owner decides that the thatcher is the best person to help.The thatcher makes progress on the roof, and for a while, everything is fine. Then, as he tears up the damaged thatching, he realised why some part of the roof got so badly damaged in the storm: the beams underneath were rotten. He describes this situation to the cottage owner, and that he'll need to hire help from the farm to fix it. "I know how to do this, but your roof will collapse soon if it is not taken care of.""But… I can't afford to pay more, I was hoping to be able to patch up the damaged part of the roof." the distressed cottage-owner explains.And so, the thatcher is caught in a dilemma: does he continue to apply his specialist skill, which is now revealed to be suddenly less valuable than before (the amount of work has increased, but not the money paying for it); or does he tell the cottage-owner that he would be better to have his roof removed and rebuilt (possibly tiled), and lose this business forever? There is not even the possibility of finding another thatcher, because there are no more in the area. The cottage-owner, it turns out, does not want to "waste" the money invested so far, and so the thatcher continues.The thatcher hires two farm workers, without whose help he could not hope to fix damage of this scale. Slowly but surely, he rebuilds and rethatches the roof, encountering more underlying damage along the way. Eventually it is complete, finished to the best of the thatcher's ability, but at great expense to the him, and at great sacrifice to his joinery work.