I don’t know much about what’s available around Ontario. Here are some comments that may be useful:
There are quite a few folk that have built-up systems completely DIY by sourcing parts from the big box stores. You could buy the individual pieces from the well-known RDWC vendors. But the prices would probably add up being more than a package deal if you were to source all Current Culture components from a single vendor individually, for instance.
If you are looking to save as much dough as possible, then you’d probably need to source stuff from different vendors, instead of a single vendor, in order to get the best bang for the buck.
There are a relatively wide range of options. Is there a certain set-up/style you are looking into / caught your eye? Are there certain techniques within RDWC you’d want to explore. For instance, using air-stones versus water-fall versus need-wheel versus ??? Bucket size, DWC vs RDWC, cooling requirements, etc? SOG/SCROG? This will help folk point you towards specific options.
Here is a recent system the @SquirtleSquad built-up :
Here is something I had put together using buckets designed for RDWC:
Here is a small system @Daddywronglegs built:
Take a look in the General Indoor Growing category as there are many DIY set-ups, too.