Epoxy coated rebar is now thought to NOT be desirable.
Original though was that the epoxy coating would protect the rebar from corrosion from road deicing salts.
Real world results have been showing that the corrosion reduction of the epoxy coated rebar was often only marginally better than plain rebar, because of the coating not being 100% intact after placement. Due to manufacturing pinholes, no coating at all on cut/sheared ends, or coating damage during transport, handling, and placement.
Some documented cases of ECR having to already be replaced/repaired in ~25 years of original installation, when the design of the project was supposed to have a 50+ year lifespan before R&R (or Replacement) was required.
Quebec has 'banned' epoxy coated rebar from public transportation projects.
Florida DOT study showed bare steel corroded in 12-15 years in a 'marine environment', the ECR corroded in 7-9 years.
One info page is here:
https://www.tuf-bar.com/application/gfrp-vs-steel/gfrp-vs-ecr/
Maybe the Canadian OP is seeing lower pricing on ECR because suppliers can't sell it for use on any public works projects?
Stainless steel rebar is a 'thing'.
http://stainlesssteelrebar.org/why-stainless/