Reconditioned/used Wahoo Kickr. Pay £600 for a mk1. £700 for a mk2 and £850 for a mk3. There is no real difference between a mk2 and a mk3 other than the ability to use the climb add-on (to raise front of the bike). The mk2 has a very useful handle. Someone on here is selling an unused mk3 for £700. If I had not bought the reconditioned mk2, I’d have gone for that.
There is no comparison with a wheel-on trainer, the flywheel makes for fantastic road feel, which is really what you are paying for above the mid-price Elite Direto. If you aren’t bothered about automatic control of resistance (which is a nice feature for workouts and climbing simulation), the cheaper dumb Elite is a good buy, but you can also get a reconditioned Snap for the same price.
Don’t be scared to pay a little more, because they are so much better to ride than an old-fashioned turbo trainer. I hated my Tacx Sartori, but two hours passes quickly on Zwift. In fact, you may find going outside to ride a pfaff!