I would recommend it if you have the income each month to spare. I'd prefer if it gave a bit more honestly, but it's one of the better deals Genshin offers and one of the few ways to consistently get pulls later into the game. What I'd suggest is that, if you do it, you save all those primos up for when a character you really want appears. If it helps you decide, each day you log-in (specifically that you log in, not every day regardless) you get 90 primos. A single pull is 160. So you're getting 2700 a month roughly - a little over a ten pull each month. Roughly a pull every two days.