The metal bit inside is available to buy but they aren't cheap. The wooden element has been added to disguise it.

The single bike version would almost certainly squeeze two adult bikes in and costs about £350. Materials for the wooden structure (based around fence posts, featheredge boards and barge boards and associated fixings) would be around £200-250 (a bit more if you wanted it longer to accommodate bins and more again if you need to 'face' both long edges with boards). Labour at £130 a day - might be just doable in one day, budget for two...or DIY.

You could save money if you are happy to just build a wooden structure to disguise your bikes already attached to existing secure points or to buy something off the shelf that offers next to no extra security and is probably less attractive.