I don't think the machine were free. You could either rent it for cheap, or buy it. There was a few revision of the hard too, but most people had a semi-old revision like v2 or v3 (don't remember exactly). Maybe in the 2000 the old Minitels were given to those who rented it previously, that way the government (well, the now public telecom company France Telecom) did not have to recycle them all...
The only free service was the Yellow and White pages IIRC. And only for 3 minutes. Well, you could always disconnect when approaching the 3 minutes limit, then reconnect. Nobody spends whole days on the Yellow and White Pages anyway :)
There was a thriving hardware market for the miniTel machines (something different about the Walled Gardens of Now, I suppose) and I recall there being some seriously nice designs. Ultimately the Minitel was a dumb terminal, but like so many of the technologies at the time, what this meant was usually just a matter of flicking a few bits.
Remember also that the 8-bit revolution was going on in the computer world at the time. A lot of savvy French got 8-bit machines they could program, or load up "MINITEL.ROM", if they wanted. One of the reasons that the Oric-1 hardware even managed to live an extra few years before completing the 8-bit apocalypse, was because the French market for nice computers that could also access MiniTel was thriving.
