The Gobi mount isn't cheap though considering what it provides I don't think it's a bad value. The mount is very clean and includes the locking handles. A comparison would the hi-lift mount that Hi-Lift sells for roll bars, etc. at $60 and the design and functionality is far short of the Gobi mount including that there is no security component.
That said, it should not be difficult to construct a mount once you find some 1" pipe clamps, or to do something through the mesh floor. Also Timgco at Expedition Hardware may have better pricing on that mount than you've seen elsewhere - it's worth a PM to him to see.