I have just the perfect one here. By here I mean in my bookmarks. Here's the link for you https://www.ls.graphics/free-mockups . I use it pretty much every time I need a mockup for tech and they have way more than just that for free. As for the paid options, trust me, it totally worth it, especially if you do design regulary. The price is quite low for the value you are getting there. Hope it helps.
