I think if you had your knives insured and lost the ones which had an unusual spec .... the Custom Shop would probably help you to get the same knife again .... it might cost a little more as a one off instead of a run .... and might take a while .... hence I agree that having spares makes sense .... but if you can only afford the "one" or find the "one" ... all is'nt lost.
Having said that .... there are some knives I doubt can easily be made again in the custom shop .... the Basic's for one .... and probably Lee's ASM grind SHBM ....
Although on the investment front and knives per se .... a good forumula is to simply get a CG model and make of it what works best for you ..... use it extensively .... and in a few years if it is the right model it will still be worth what you paid and a bit more.
The CG NMFBM's were in the $ 350 ish price bracket IIRC and now go for $500 + in unused ..... a satinised stripped user will still have you getting your money back .... maybe even more depending on your name as a modifier .... Horn Dog does well and so does Norcal .... and Ban makes a business out of it ....
But the longer you are working with knives the more you know what works for you .... the KZ has not been as popular as a khukri design could be and second hand values have dropped .... but if modified a little it is a pack knife which can compete with a small axe and be more versatile .... and has a place in a set of knives if it is something you can use .... but thankfully for me mine works that way "for me" .... I would be disappointed on losing a lot of money on this knife as some have done when selling them compared to the factory cost. The KZ tho' is the only Busse I can think of which has done that and it was a TT model .... which by implication was done to get the final model right. I seriously doubt the final model will be anything but a huge success ....
Most Busse's you can use and recover your initial cost on if bought at factory prices ....
LE's off the exchange are a bit like buying a classic car .... you might need to showcase it to ensure it holds it's cost value .... but the BWM LE from the factory I reckon you can use it and when it is not made anymore it will jump in price .... and a SPA treatment on it is easily done .... so those LE's will see you get your cost back and perhaps more and enable you to have a user.
Just my $0.02 on this .... but I think Ank is doing the logical thing by using a CG and safe queening the LE .... feeling heavier and more substantial is'nt always a translation to performance .... just look at the KZ .... you have to thin it a bit on the zero edge .... IMO you need to do the same with the NMFBM CG to get the best "zero convex edge" .... zero edges are not just about the zero aspect .... they are about the shape of the convex grind .... a zero grind can be Pear Drop shaped ... Tear Drop shaped and Apple Seed shaped .... these are basic descriptions used to make it clear a zero edge is'nt a universal one .... but if you look at Japanese Swords they have a whole vocabulary to describe the shape of the convex grind .... because over the centuries Swordsmiths would refine the ideal shape for cutting .... like a racing power boat hull is refined for cutting through water .... and you don't know what works best till you keep chopping wood and working with your knowledge and grinding skills to change it .... swinging through "air" and having a "razor sharp edge" is only part of the story when it comes to a zero convex edge .... heavier and feeling more substantial does'nt neccessarily equate to "chops better" if lightening the knife by refining the shape of the convex grind improves the performance more than leaving the weight on the knife for greater impact energy ....
The Basic 9 in standard form out chops the SAR 8 zero grind in standard form despite being a lighter knife ..... the reason being the edge and the flat grind offering little or no resistance .... the SAR 8 can be brought to equal the Basic 9 but only if re-profiled. The difference lies in a "Pear Drop" shape being taken to an "Appleseed" shape .... which in my experience works best ....
But this is just my opinion .... based on chopping a lot of wood and re-doing the grind slowly bit by bit till I had it right .... your mileage might vary .... if you use a zero grind LE from the factory and can sink the blade in to the spine .... you have a knife which cannot easily be beaten on performance .... they all don't go past the spine IMO .... you need a sword to do that .... but if it does'nt hit the spine .... let me say that it "can do" if it is re-profiled ....
hence my preference for saying a CG NMFBM stripped and re-done is for me at least the best option. Doing the same to a much more expensive LE version is'nt practical for me as Ank has pointed out because you will just loose a lot of money if you came to sell it .... as like as not the LE number would'nt be there .... as per HD's reprofile of his Killa Zilla ....
A good way to test the edge profile is on limbing .....
When the knife can do a limb in a single cut which is as deep as the blade then you have the profile right .... or if it can get better I have'nt managed it and would welcome any insight on how to get beyond that benchmark .... so for those who want to use the LE's and can better that let me know what or how you are doing it. For me I think I am the "limiting factor" .... a lot of it is technique but if I had 230's arms I reckon I could do more but I doubt the knife would be any different .... and hence why I said the CG NMFBM zero convexed is a good option.