Hi. Could you define what public transportation means to you in this context? Do you mean not driving yourself? Would a privately owned coach service count as public transportation for this purpose? An airline? What are you trying to achieve by using public transportation vs the cheapest way of any kind?

@ZachLipton Technically you may be correct to question the definition of "public transport", but I think it's clear what is meant and this is good opportunity to demonstrate our helpful and welcoming side.

No, we do need a definition here. What is the exact intention of the OP? Are we talking about publicly owned companies, or 'not traveling privately'. Is the EuroStar train 'public'? Are privately operated bus companies like EuroLines and FlixBus a good answer? @Muhammad, please edit your question and describe exactly what modes of transport you want an answer for.

en.wikipedia.org/wiki/Public_transport

Can someone please detail how this fits WANTA? The question seems quite precise to me

I think this set of comments demonstrates everything that's wrong with Stack Exchange. And I can't see how the question can possibly be off topic. :-(

You get me worried about your financial situation. You want to travel between two of the most expensive cities in Europe and spends months in one of them and you worry about the price of an air ticket? Or even a normal bus or train ticket? Say €100 or so. That is less than half the daily budget of a normal tourist in Paris, even a low budget tourist is likely to spend as much as that each day if 'doing' Paris.

@Willeke there are any number of reasons why somebody could have room & board for 2 months in Paris, but very little free spending money - staying with relatives, student program, etc.

@JohnFeltz, true, but even in such cases, Paris is an expensive city and the cost of flying or normal train tickets not that high.

@Willeke A bed in a dormitory costs around 20 euros in Paris, less if you plan to stay for two months. Food costs around 5 euro a day if you cook for yourself (possible in a lot of hostels). Add to that a weekly budget of 25 euro to visit stuff and you have a low budget traveler. No low budget tourist is ever going to spend 100 x 30 x 2 = 6000 euro for a two month stay in Paris.

The question seems very clear to me: the OP wants cheap. I have no doubt that public just means available to the public and not necessarily run by the government. Maybe even a plane would be acceptable if someone knew an unusually cheap service. For example it might be worthwhile for the OP to check Southend airport.

Hitchhiking, bicycling, and walking are “available to the public.”

@anomuse because its crux (in every edit) is a ”shop for me" question, which is OT on any stack but a couple. And b) SE tradition calls for askers to ask after they have made their own effort and are stuck, and that effort is not evident in the question; clearly there though, since OP answered their own question finely. Unclarity around meaning of "public transport" is not much of an issue, I presume it to mean in this context "anything that will transport a man and a couple suitcases for hire".

@JanDoggen you cannot be serious ?

No need to be anal about this, lol. In general english understanding, public transport = transport not performed by yourself or at your own direction (i.e. not your own car, not walking, not a plane you own or lease yourself). How on earth can that be unclear. Jesus.