There's an upfront purchase price (I think mine was in the region of £450) and then a monthly fee. They haven't taken a monthly fee off me yet, because it's only just arrived. Apparently you can pause the monthly fee if you're not using it for a while, a bit like putting your car on SORN. The process of buying it was so easy and crap-free that I don't know whether it is closest to a subscription or contract model. I'm not a big mobile phone person myself, but I keep my partner Xylia in mobile phones and enabling her to enjoy the latest iPhone is always a morass of bureaucratic junk, credit checks and the like, whereas with Starlink all you need is an address and a debit/credit card number and you've got one.
Another fun thing is the way it's a motorised dish, so you can see it moving around all by itself hunting for the best signal. I had wondered how it would perform here in the city with buildings all around, but it found a signal with no problems.