"You can get an RF 50mm f/1.8 for about $170 and an RF 35mm f/1.8 for about $450."
When somebody asked the question the OP has asked somebody always recommends the 50mm f1.8 prime and or the 35mm. Yeah, they are fast lenses but that is where there usefulness ends. Can either or both be used, of course but are they easy to use and that is ano they are not. Better choices abound. Remember comparing some top quality zoom lenses to the fast primes some only offer little more than a one stop advantage. Not a deal maker or breaker. Money not a factor get the Canon RF 28-70mm f/2 L USM Lens. Or the RF 24-70mm f/2.8 L IS USM Lens which is a bit less expensive at the cost of a stop.
However in any case the lens you have is always better than any lens you wished you had so if a 50mm f1.8 is all the budget allows be prepared to work with it.
EB
EOS 1DX and 1D Mk IV and less lenses then before!
