Yeah, if you buy cases and front panels from them as well, it does drive the price up. For most people the metalwork is the downside of DIY but if you can do it yourself it works out much cheaper.
Most US DIYers I know use par-metal for cases.
http://www.par-metal.com/
As you can see from the pic, mine has a blank front panel but for something like a pre with simple controls that doesn’t bother me. For eq’s and comps etc it’s a different story. If you wanted to have a nice drilled and engraved front panel made you could try front panel express.
http://www.frontpanelexpress.com/
Realistically, with the case, PSU, connectors and everything you are looking at $150-$200 per channel, not cheap but very good value in my opinion considering the quality. Like I said in my review my 4 channel unit cost roughly £400 ($800) but I used some fairly pricey transformers in two channels (Lundahl) and I didn’t use the cheapest opamps either.
The BA and the BAD (Baby animal ‘dual’) are two different pres by the way, the BAD being more expensive.
I’d say these types of kit are ideal if you’re starting out but it might be wise to try a cheap guitar pedal kit or something first just to get your soldering skills up together. Modern PCBs with solder pads are pretty easy to work with though once you get the hang of it.
Some alternatives (I hear good things about both of them but have no personal experience).
http://www.seventhcircleaudio.com/
http://www.fivefish.net/diy/
and found your earlier post about the baby animal. Looks like it costs a little more than I was hoping to get it all together. If I understand right, the kids that come with the box and everything are the more expensive kids at the bottom of the jlm page, not the cheaper ones that say "Complete BAD PCB kits."