Click image for larger version.  Name: Steel Frame BOM.PNG  Views: 481  Size: 55.4 KB  ID: 10227I spent some time today calculating the cost of the steel. Not sure its a useful metric (for discussion) but there are just over 30M in steel box in the design. I was quite dismayed to start checking on the web for pricing only to discover several sites quoting around £350, which was more than I had in mind. Then I came across a company called ISG Steel who routed my call to the nearest depot (I live in Berkshire). Thier quote on a like for like quantity of 50x50x3 steel box section was around half the websites I'd found up to that point, also they were friendly and when I mentioned I needed more than just the one length offered me a discount. From then on in I looked at how to cut the required lengths from 7.5M stock and came out at 4.2 lengths, which was dissapointing. I modified the design to use small 5cm lengths of steel to support the bed on each of the 5 side member points, instead of a continuous rail (Orange in the picture above) and that nicely got me to all the steel in 4x7.5M lengths. Once I asked for a quote including the top rail material of 90x50x3 the whole thing with shipping came to £220. It seems a fair price and much better than many of the websites I found.