20 euros per month with "Free" (that's the name of the company) ISP.
"Free" has his share of problems, notably many people complain that the quality of their connection is strenuous at best, some people don't. It's a bit of gamble with them.
What can't be denied is that in France there was a before-Free and an after-Free. They introduced 20gb for 20E/month when everybody else was at 5gb for 50E/month (not the exact amounts, but it was that ballpark). The result is that the other ISP had to align themselves with Free, and now you have a lot of other similar offers to choose from. Yay Free.
Yes I think France had the same problem we have (and are gonna have again) in The Netherlands.
We used to have a lot of providers, that merged into three big ones (KPN, Vodafone, T-mobile). Despite them not colluding, they basically price-matched each other which meant we had some of the highest prices in Europe.
Then Tele2 came into the market as a new player.
Before Tele2 it wasn't uncommon to pay €20-30 for 2GB of data + 100 texts/minutes. Tele2 started with 25GB (don't know the texts/minutes) for €25, and now it is €25 for unlimited.
Plus there are many MNVOs offering even cheaper prices, and this all combined forces the big three to follow the market.
However, T-mobile is going to buy the Dutch part of Tele2, so now we will have 3 big players again, and it is almost certain prices will rise and innovation will slow. The EU even did research and concluded that for a healthy competitive telecommunications market you need at least 4 providers.
Edit/extra info:
We have a regulatory organisation (ACM) but they are utterly spineless. For example, in The Netherlands KPN used to be a state company, and when they were privatised they basically got the entire copper grid for pennies on the euro. Because of this the ACM later ordered that they must allow other companies to hire those lines. This is all good.
But then there is the cable grid, which was built by private companies and then in the end either owned by UPC or Ziggo (so duopoly on our cable grid). ACM then allowed those two to merge, resulting in Ziggo owning ~50% of the internet market in NL, and being a monopoly provider in a lot of parts in The Netherlands. You guessed it, they have raised prices 3-4x in the last few years, waiting times for calling customer service went from a few minutes to 20+ minutes.. etc.
For clarification: in NL due to lots of mergers (and because the companies are aware that landline internet will go the way of landline calling) most telecommunication companies are both landline and mobile providers. You have Vodafone-Ziggo, KPN and T-mobile.
"Free" has his share of problems, notably many people complain that the quality of their connection is strenuous at best, some people don't. It's a bit of gamble with them.
What can't be denied is that in France there was a before-Free and an after-Free. They introduced 20gb for 20E/month when everybody else was at 5gb for 50E/month (not the exact amounts, but it was that ballpark). The result is that the other ISP had to align themselves with Free, and now you have a lot of other similar offers to choose from. Yay Free.