The trouble with cheaper lines is threefold. Their breaking strength is inferior to the fly shop brands, they’re usually a bit stiffer, and the manufactured diameters only go down to about 4X — usually.
Then a couple of years ago I bought Seaguar Finesse. It was hard to track down when it first came out, because here was a line sold in smaller quantities, with a higher than expected price tag (for the gear guys). But to fly anglers, the 150 yard spool for about $20 was a steal. Easy decision. I bought it immediately, based on Seaguar’s own description and the specs.
Since then, Seaguar Finesse has become my go to fluoro tippet material from 2X to 5X, and a few of my Troutbitten friends do the same. It’s thinner, but stronger per diameter, and is indeed more flexible as described. (It has some finesse.) It’s as almost as good as some fly shop brands and better than many others. And because the type of tippet we use is not what catches trout, I don’t overspend on tippet . . .