Do you actually get a chance to test instruments in a store before buying, or are you pretty much stuck with online? Because honestly, that's the huge difference between a ukulele that's gonna keep you motivated and one that'll turn you off after two weeks.
Budget-wise, don't forget that between $50 and $100 you're mostly getting junk that sounds hollow and has terrible action (string height) to play. It'll just tire out your fingers for nothing. Once you get to $120-150, you start finding stuff that actually holds up. Brands like Kala, Mahalo, or even the smaller Fender lines in that range - that's solid without being crazy marketing hype. It's just that the real entry price really isn't $50, even though you can find it everywhere online.
One thing nobody ever mentions: when you buy online, set aside $30 to go to a local luthier or instrument seller and ask them to dial in the action and tuning. Seriously, a ukulele from Amazon often arrives not quite right, and five minutes of adjustment will completely change how it feels to play. It sounds silly but that's literally what separates "I'm giving up after three sessions" from "I'm sticking with it".