The owner of the Annapolis based Figaro 3 chartered a boat for the season in France as well as attending a school over there in preparation for the A2Gr that got canceled. He said it was somewhere around 80k in costs (he provided his own sails) I have no idea if that is just the boat or included flights back and fourth housing, ect. He explicitly mentioned that the school was cheap (~100usd a day), I think it was training with Tanguy Le Glatin in France. He also hired he Sidney Gavignet to come over here and teach him the Fig3 and that was not cheap. If you want to get in touch with the Fig3 owner I'd be happy to help or you can try to reach out to him through Beneteau. I am absolutely in love with the Fig3, fantastic boat, very forgiving at the lower skill levels but tune-able enough and challenging at the top that the IMOCA and Class40 guys are racing and loving them. It is however a horrible light air boat, and at least on the east coast of the US it is difficult to get insurance to race (or even sail) a boat sub 35ft offshore.
I've looked heavily and drafted a budget to do the Mini itself but there is a substantial time and money investment difference between finishing and competing. Competing would be 2 year campaign in France and a newer boat (~80-150k), finishing I estimated 1 year sailing the boat in the US with an american based coach (Joe Cooper, Nathalie Criou, Jerome Sammarcelli, ect who know this type of sailing), and then another year of part time investment in France to qualify and see how badly I sail compared to the french Mini sailors. I had planned on getting a 600+ numbered boat ideally a 750+ after I had lots of work and issues with my 400 sereis boat that I (and the new owner) had to fix. Remember that qualifying on a Series/Classe boat is much harder and spots fill up faster than those of prototypes (mostly due to limited availability compared to protos). Also remember that doing a non-european qualifying leg can be tricky, I would suggest something like soloTP, B1-2, or A2B that would allow you to compete and give you a support fleet should something go wrong but you'll need to co-ordinate that with the Mini RC. The Mini NOR is available in English as an FYI, I'd read that ASAP.
I can also tell you that Pogo is very responsive via email (I spoke to them recently about the foiler), as is the Mini Classe itself and they are happy to help you (in English) answer any questions you have. I know a new pogo 3 is somewhere around 80K eur, and shipping from france to the east coast (Baltimore) was right around 6Kusd when I was pricing out 888. Another resource to reach out to is Jay who built Speedy Gonzales, you can find him and his wife via their facebook page "The Coconuts sailing Team" they can be slow to respond but have been a great resource, I talked with them about visas and how to sail in France, but this was before COVID.
If you are serious about pursuing this I would buy a boat in the US to get an idea of what a mini is like, they handle like dinghies, and don't like big swell, if you aren't used to it and not running 110% all the time a proto will chew you up and spit you out, I had mine up to 23knts, and to give you an idea of the sheer power, I bought used M32 kites for practice sails. My old boat (415) is for sale in FL and has seen a $40k refit, and an incredibly well equipped RG650 is for sale in Annapolis, both of these boats have issues associated with them if you were to try to use them for the transat, but they are both probably capable of doing the race but neither would be competitive. There is a Tiptop for sale in the classifieds here that seemed to have been kitted as a cruising boat, and I'm pretty sure a US built pogo 2 will be on the market very soon.
Another thing to note, if you buy a boat and sell it in the US you will take a huge loss, and even then potentially sit on it for years.
I hope this helps, I haven't been able to pursue this dream very much further as I either have the money and no time, or time and no money. The year I bought 415 I spent 6 months in the arctic, and came home in the winter so when the opportunity came to sell I jumped on it....
Also link to the Mini listings, http://oceanracers.net/boats-for-sale/