Canon has backed themselves into a wall with their lens pricing, especially with f/2.8 IMO. Asking 2200-3000 per lens means that both Sigma and Tamron will be able to move I to a 3rd party market with a strong following. If Tamron can maintain the quality they have in the SP G2 series, it will be killer. I rented all the lenses I wanted to try out before I made my decision but in the end all of my f/2.8 glass is Tamron. Some faster primes are Canon or Sigma Art series. Canon isn't even competitive anymore. Price vs quality doesn't make it up as some third party lenses have better quality housing and the differences were slight with certain tests being won by third party glass and others with Canon L glass. With the number of camera sales diminishing yearly, you would think that Canon would want to take advantage of RF glass for marketshare
The lens pricing will lower. Canon always has a very high price for lens on release, then they go down with time.
Sigma is really upping the level with their art series thou, pity they almost always have that yellow cast (all the ones I tried. Tamron have nice colour rendition and are up to speed lately.