Chastity and orgasm denial discussion

I’m in the market for my first chastity device. The Attica from UberKinky keeps drawing me back. I realize £60 is pricey compared to dhgate, and I understand that its hinged rings are generally considered a drawback here. What wins me over is the length - 2.5” feels just right; I’m not keen on those very short options available on dhgate, nor do I mind that it comes with multiple rings. Since I have no prior experience, I don’t know exactly which size to get and expect some trial and error, likely starting larger and working my way down. With the dhgate devices, you only receive one ring at checkout. Sure, you can order spares, but they cost almost as much as the device itself - buying all four would bring the total price in line with UberKinky’s offering. The dhgate option is still on the table for me, though I’m curious if there’s a dependable way to figure out the correct ring size. I’ve attempted using a string loop method, but because my tension has been inconsistent, it yields quite a spread of measurements.