For such limited usage, it’s absolutely not worth monthly. Unlimited for X amount is only good value if you’re making enough use out of it to outweigh the cost of PAYG. I used to travel for work and even at a bargain price of ~$10 for 20GB/unlimited/unlimited, I was only really using my data for Spotify while driving so come the end of the monthly cycle, I’d have an evening of watching YT or whatever else on my data since I’d still typically have about half left.