I pulled the 5 frame NUC plans off the Beesource and whipped together 4 NUCs a couple of Saturday's ago. Needless to say it was pretty easy and straight forward. I have a router so doing the ends was quite easy, used lapped corners instead of box joints - I just can't see the value of box joints in a NUC box that doesn't get a lot of weight stacked on it.
All said the cost was less than $10 each and the time was only about 2 hours to build all 4 of them. They turned out comparable to the $20 NUC kit I bought from Dadant last year and the design is similar.
I have not been very happy with the frame feeders I use in the NUCs. Even with floats a lot of the bees drown. So I pulled out a round door knob drill and cut a round hole in the cover of each NUC. Since I don't plan to overwinter in them - these are starter hives to allow buildup before going into a full sized deep I don't mind having this hole there.
Then I scraped up 4 plastic jars like peanuts, almonds and even rice come in. These hold about 2 or 3 quarts and have plastic screw on lids. I tried punching holes in the plastic but some of them split. My smallest drill bit was too small so I hit on the idea of heating a large needle (found some in my wife's sewing machine box). Just held it in the flame of a lighter and it melted a nice thin hole in the plastic top. Now I've got a nice set of hive top feeders that sit on the holes of each NUC lid. Four NUCs cost about $36 Four feeders cost zero.