Yes, Patty Mold sets are fairly common (at least the sets shown above)... :)
These were made my quite a few manufacturers, with the most commonly collected ones being made by Griswold, Wagner, and Alfred Andresen...
The sets above, I paid less than $20.
Now, Griswold also made a LARGER set or the Deep Molds, with no. 3 on the bottom (with handles).... Those are NOT common, and are Hard to Find.
(as far as we know, they were not a 'boxed set'.
A set of those may set you back $200 or so....
(unless you are me... I got a steal on mine! ;) )
Then there are several different styles of 'Patty Bowls' produced by Griswold alone... they can get a bit more expensive than the one shown in the set above, which is the No. 72, and very common.
Molds and handles are still produced and available today:
https://www.fantes.com/catalogsearch/result/index/?limit=all&q=patty