You can get outstanding results with a $100 mic and proper sound insulation/mic placement/voice technique and with post-processing (eg EQ, gate, limiter, compression, de-essing - to sweeten audio, remove background noise, make audio levels consistent, etc). (I’d also budget a mixer/interface [because I’d probably choose an XLR mic for greater choice and flexibility], a boom and an extra windscreen - but they’re not essential.)
If you’re looking for a simple plug-and-play USB mic you limit your options, and if you don’t consider spending money on eliminating reflections or post-processing you’re going to get inferior results even with $500 mics. There are entire podcasts that go in-depth on podcasting gear, technique and related issues.
If I remember right, StarTalk Radio started out with a $150 Audio-Technica AT2020USB+ USB mic, won an award or two, no one complained about the sound, but then they got the budget to go upscale.
If you’re screencasting with yourself in the picture the boom will be in the picture - you need to be that close. Booms offer flexibility but don’t expect them to work with podcast mics like TV/movie booms do; they need proximity.
Everybody makes a boom (and Chinese manufacturers make cheap knockoffs for a fraction of the price). This article highlights the better recommended models, which will run $100+.
If you’re looking to get a simple USB-based podcasting setup with a boom I think the bang-for-the-buck choice is the $220 Blue Microphones Yeticaster Studio package, which comes with mic, shockmount, boom arm, C-clamp, PreSonus Studio One Artist DAW software (usually around $99, and included with some audio hardware) offering pro-level mixing capabilities, and
iZotope Ozone Elements (normally $30-70) for EQ and imaging via nearly 100 presets.
It’s very easy to spend 2x-5x as much for better performance, so of course it depends on one’s real needs and one’s budget. I have a lot of experience with audio, not much specifically with podcasting, though. But there are plenty of sites, subreddits and YouTube videos that will offer tons of advice at different price levels.