We love our Tempur-Pedics. DW had one before I met her. I liked it so much, I bought one for my place. When we finally bought a house together, we kept both Tempur-Pedics. We use one and keep the other in the spare bedroom. One of the reasons we don't travel for longer periods is that we miss our Tempur-Pedic!
We paid about $ 1K almost 15-20 yrs. ago. Honestly, they feel as wonderful today as when we first bought them. No obvious lumps, sags, or other issues. It's hard to believe, but they seem just as good as new, or someone we have adjusted to any, presumably small, changes.
We bought the one and only model available back then. Now their website has several levels of firmness, starting at about $ 2K for a queen size. We're definitely hanging on to our spare! I'd suggest somehow trying one at least overnight before buying since they are very different.
It takes a bit of time to get used to the memory foam style if you've only slept on spring mattresses, in part there is so little movement, no sense of "bounce". This is good, though, for turbulent sleeper or if your partner gets up a lot overnight.
The foam does tend to retain body heat, once it warms up, which can take a little while in the winter. We just run the A/C as needed regardless; no pinching pennies when it comes to sleep.