These are lovely as collector's pieces, but it would be foolish to expect any functional advantages over stainless-lined copper from Mauviel / Bourgeat / Falk (which are all essentially the same). And tin brings with it significant disadvantages. No matter what anyone tells you, it is fragile. In a saucepan you will abrade through it with a whisk if you whisk a lot (which you will if you are making things like emulsified egg sauces, which are arguably the only kinds of sauces delicate enough to demonstrate the benefits of copper). Forget about sautéing. A proper sear requires preheating above tin's melting point.
The conduction differences in a metal layer that's less that 1/10mm are insignificant. There is no "non-stick" advantage to tin. If food sticks to your cookware, you've got technique issues.
There are still a couple of places in the country that re-tin cookware. Look at $70+ for most pieces. Not a big deal if the cookware is decorative, but that will add up if you use the stuff hard.
I wouldn't consider thickness beyond 2.5mm an advantage. You will get more heat retention and more evenness, but at the expense of slower responsiveness. And responsiveness is the real reason to use copper. You can get evenness and heat retention for miles from heavy aluminum, at a fraction the cost.
Unless decoration is your primary concern, I would be wary of spending money on any copper. I love my 1.5L windsor pan because I'm a sauce geek, and because this pan is made for the things copper does best. But let's be honest ... look in the kitchens of Michelin 3-star restaurants around the world. If it isn't an open kitchen (on display) and if they bought their cookware this side of World War 2, they're probably using some kind of laminated stainless. The differences are vanishingly small in practice.
I use my 2.5mm copper because I bought it when the stuff was pretty affordable. I also use laminated stainless / aluminum, disk-bottom aluminum, heavy aluminum, cast iron, spun steel. The laminates get the job done as well as the copper. They just don't look as awesome when they're doing it. If you work out the physics calculations, copper has an edge in some situations, but it's not going to influence your real world results. You could save the money and get an immersion circulator or pressure cooker or something that will give you serious new powers in the kitchen.
