Best site in France for used stuff in general is Leboncoin.fr . Here's a
LINK that searches a 50 kilometre radius around Marseilles that returns some dinghies less than 3000 Euro. Other searches reveal plenty of outboards on their own. You can of course use google Chrome and translate to English.
p.s. this one in Toulon (close for hubby) looks pretty good for a reasonable sized rib with a pretty new engine...
https://www.leboncoin.fr/ad/nautisme/2762721876and a little one with electric outboard right in La Ciotat...
https://www.leboncoin.fr/ad/nautisme/2768153393