I bet it would take about $100 and a bunch of fiddling to get that to work right assuming all the parts like the flow restrictor are there. It doesn't even have the good push connect fittings. A new one can be had for $140-150. Less if that other canister is a DI in good condition.
Just buy this next week: http://www.bulkreefsupply.com/store/75-gpd-ro-di-5-stage-standard-system.html
The new one will come with all the fittings to connect to the supply line, be plumbed correctly and ready to hook up, and have instructions as to which line goes where. Then figure out if that booster pump works and sell it to offset your costs.
You could get that to work - it is just a plastic housing after all, but without being familiar with how it should be setup and how the water should flow through it (it does matter what direction t goes), I recommend just getting a new one.