Is RF100-400 right for me

[carvat]

Hello, I am an amateur photographer primarily shooting wildlife (mostly birds) using an R50 and 75-300 iii with an adapter. I know the lens is typically regarded as one of (if not the) worst telephoto produced by canon, so anything may technically be an upgrade. But as someone shopping on a tight budget, will waiting on a used/refurbished RF100-400 to go on sale for ~450 or less be the best option? As far as I've found it seems to be the best which can be found within that price range.

[Tronhard]

Hi and welcome to the forum:

The RF 100-400 is a good value lens and certainly a massive upgrade over the EF 75-300, and its weight and bulk should balance nicely with the R60 body.  The RF 100-400 offers much better optics, larger focal range and reach, and has excellent image stabilization - all of these elements will contribute to making your imagery better.   So, I would suggest that you do wait for a deal on this lens - your budget is not far off with the current Refurb version being $520.  So, if you sold the EF 75-300 for $70 you would make up the difference.
Shop Canon Refurbished RF100-400mm F5.6-8 IS USM | Canon U.S.A., Inc. that said, I am not sure how much lower the price will drop in the current market - that is a decision you have to make.

Here are a couple of reviews on the lens:
Can THIS Lens be ANY Good? | Canon RF 100-400 | SURPRISING Results (youtube.com)

Canon RF 100-400mm Review for Bird and Wildlife Photography (youtube.com)

[ebiggs1]

"As far as I've found it seems to be the best which can be found within that price range."

Any lens you have is better than any lens you wished you had. You have to by what you can buy. I might suggest you look for one of the 150-600mm super zooms on the used market. They are good candidates to buy used since they sometimes get very little use. The Tamron G2 being the top choice but not as readily available used at your price point.

[March411]

Good day carvat

Many of us own the RF100-400 and get very nice results from the lens. It is light, has good range, pretty decent IQ and will marry up nicely to your R50. That setup can easily be carried all day. 

It was mounted on my R6 but here is an image taken with the lens in some fairly poor light. It's not the fastest lens but it would be a nice addition to your system at a very reasonable price.

[shadowsports]

+1 for the RF 100-400 on the R50.  I purchased mine to replace a EF 70-300 USM II I used adapted.  It provides the extra reach I wanted and in native RF mount.  I used it for several months and then bought the RF 100-500.   The 100-400 is perfect for hikes and travel when a lighter weight lens is desired.  I have a full frame body.  The RF 100-400 would pair nicely on a R50, an APS-C based camera.