The audio quality from your home studio setup is important but it's equally important not to overthink your sound. It's easy to get obsessed with your recording space but that isn't where you should be putting all your energy. If you want to obsess about something, obsess about your performance. Expensive microphones don't book you work. Your script reads do! This doesn't mean purchasing the cheapest USB mic, plugging it into your laptop and recording in your garage. You'll need some gear and a decent recording space, but this can be done inexpensively.
Research Rode microphones and Focusrite preamps. They're cost-efficient and as long as you have a well-treated space, you'll be in good shape! Unfortunately, the space often gets taken for granted in the voiceover business. I think Jan Anderson, who conducts our home studio setup sessions with our students, would agree with me! You can buy the most expensive gear on the planet and your audio will sound lousy if you're recording in a massive room with hardwood floors and high ceilings. Work with a coach like Jan, who can provide professional guidance when setting up your home recording studio.
Sometimes you need to get creative. Many talents use large walk-in closets for their home studios. This works rather well but make sure you have plenty of ventilation and even though it may be the smallest space in your home, you'll still need to treat the area with Auralex foam or moving blankets. Whisper rooms are popular and work exceptionally well but they can be pretty costly. There are several cost-efficient and creative ways to treat your recording space without breaking the bank.
In the end, it's your voice and script reads that the client is interested in and most of the time, they have someone producing and engineering the project on their end, so you don't always need to have the most outstanding audio on the planet. A good producer can do a lot of magic with audio that isn't perfect. Professional? Absolutely! But you don't need to spend months and months trying to get the ultimate sound out of your recording space. Your performance skills are what books you the gig.