I absolutely love some of the custom works of art that I have seen. Some of the better bladesmiths make you want to buy a knife just for the joy of owning it, even if you never used it.
However, not all customs are of that calibre. I see pictures of custom knives that would not have left my place if I had built them. Some have defects that are obvious even in poor pictures. Even IF the knife is acceptable in terms of fit and finish, there can also be a problem with many makers heat treat. Some of that is an attempt to use supersteels that they are unable to properly heat treat, other times it is simply a lack of knowledge.
Really, if similiar knives are compared, I would buy a production knife over a custom, up until the point that what I wanted was unavailable in a production knife.
D2 or O1 steel, fixed or folder, is available with many handle materials and styles with no wait time, for less than $100 in many cases. Heat treat, fit and finish, and value will all be quite good. No grinding marks in the bevels or on the spine, well made sheath with straight stitching and finished edges, attractive designs, etc.
If I wanted a damascus blade bushcraft knife in shape of my own choosing, handled in desert ironwood with mosaic pins, with two sheaths, yep, custom all the way.
Really, it to depend on what you are willing to pay. I can count on one hand the custom knives I have seen in the makers area for less than $100 that could even be considered against a production knife. Some makers with the proper experience and tools can build and sell knives that are quite good as you get close to the $200 mark. Even then, only some are actually better than production knives in my opinion. Many still sport finish problems or poor leather work visible in the pictures at a price point over $150. There is a reason that many very good looking customs cost several hundred dollars or more, and it is NOT because the maker is getting rich. He could actually be making the same wages as someone who makes a $100 knife, but is putting in the time required to make a proper product.
A recycled steel with unstablilized wood in a low quality leather sheath doesn't compare to a production knife. Similiarly, a more complicated steel with a backyard heat treat and sanding marks do not compare. These are knives that a person makes for the joy of making them, then gives away. I have handled customs with ivory handles and 80 grit scratches in a polished blade, as well as coated knives that were stuck to the box, leaving bad marks in the coating. Some LOOKED very nice, and had a nice feel, but the maker was using lawnmower blades, and had no idea what a heat treat was. Those last ones he was attempting to sell in the $200 range, due to the time he had put in on the fit and finish. These were knives from 3 different makers.
By the time a maker buys quality steel, stabilized handle materials, leather, sanding belts and paper, pays for a grinder, forge, shop space, etc. the knives HAVE to cost more than a production version of the same knife.
Compare a simple knife like a KaBar or a Buck or a Case. Show me a custom that has the same fit and finish, attractive design, and properly made sheath as a Buck Alpha hunter, or a KaBar military knife, or a Case hunter, for less than 2-3 times the cost.
Whether a person wants to buy a custom or not, great. The idea that there is any comparison between a similiar production and custom knife of a similiar cost is an absolute joke.