Sheesh...
Look mate, anybody can take a large, cheap PC tower case and using a hack-saw, nail gun, screwdriver, cutting-torch, jackhammer, duct-tape, superglue, doublesided-sticky-tape, blu-tac, string, chewing gum, etc make their old Amiga motherboard fit and work (I believe Redrumloa did this).
The fact that Elbox can take a stock tower, modify it and supply the parts and instructions to allow Joe-Average to rehouse his motherboard safely and easily WITHOUT destroying it in the process is PRICELESS.
You haven't been gouged, ripped off, swindled or anything. You've bought an excellent tower kit from a proven supplier. If really was easy to re-house your A3000 mobo then you wouldn't have paid Elbox for their kit.
Please don't knock a company for supplying essential items to the dwindling community. You don't know how much each modified tower costs to complete and the fact that someone is willing to provide a professional product to such a limited consumer base is to be applauded.
On the other hand, if you feel you can buy these $45 towers yourself, modify them, supply all the parts and instructioins necessary and market them for less than Elbox then go right ahead. I may even buy one off you myself... :-)
Oh, and you need to look up what "remanufacturing" in the context you've used it implies before you get sued.
