I have seen sheaths advertised at $16 and change so if I can buy one for $5 assuming I would want to who's selling at these prices? The prices for these knives as is the case for all easily obtainable mass produced items is all over the board but lets take $45 as an average.Back out the sheath at $16 retail and that leaves us with a knife valued at $29 retail. So if we are to use these numbers which are approximate the cost of the sheath represents over 35%of the total purchase price. I realize that many like the factory sheath and the carry options it provides. To me its a worthless piece of plastic that adds to the cost of a mass produced knife. I wont use it anymore then I will use the pieces that come with the optional kit which thankfully is an optional purchase. Kinda like the optional scales. Some like to wrap the knife, some leave it as is, me I like the scales but if you don't like or want the scales and are going to remove them any way why pay the additional freight. Your choice.
Lets try comparing apples to apples.
you say you can find a hand made custom kydex sheath for the Izula for $16. That's a great deal. jump on it - I haven't seen any that cheap.
MSRP for an Izula is $81.08. $81-$16 = $65, not $25.
This is not a $16 piece of plastic. It may cost them $5 to make, it may only cost $1.50 to make - but it would cost the same amount in time and labor for packaging if it were only a cardboard edge protector. Shipping in a fixed rate container does not cost any more with or without the sheath. Especially if you're ordering from a company that offers free shipping.
online retailers have it at the $45-55 price point, shipped in an "injection molded, mass produced, good enough to keep it from being damaged in transit" sheath. If you don't like the sheath, throw it away or post it on the exchange - see if you can get your $16 out of it that way.
Even if a dealer were to sell you half a dozen knives with no sheath, you'd still be paying $45-$55 each. If you want to spend less, set up a dealer account with ESEE - then you can buy everything at dealer cost. (which is still more than $25 per knife)
If you think all neck knives are worth only $25-$29, you have literally dozens of other products to choose from. Buy one of those.