To be honest Alex, there really is no such thing as "close to stock" when it comes to radios. It's either OEM, or Aftermarket which will be very different than OEM (in terms of both looks and functionality).
If you prefer to keep the look and feel of OEM, a quick eBay search has reveals a bunch of 1st generation Xterra and Frontier radios in the $160 range. Some are even the 6 disc in-dash unit for that price. I even saw a couple of very basic single disc OEM units going for about $90.
If you go aftermarket, just understand that
all aftermarket radios will require at least a wiring harness and possibly a dash kit. The good news is, these items are very inexpensive online at places such as Amazon or eBay. Stereo shops will charge you an arm and a leg for them, so I'd stay away from Best Buy and the mom and pop shops for those accessories. The installation of an aftermarket radio will actually be very quick and easy with these accessories.
Personally, I'd recommend that you use the opportunity to upgrade to an aftermarket radio with Bluetooth. It's a game changer in terms of taking phone calls while you're driving, and streaming music from your phone. You'll wonder how you ever lived without it. Take a look at the Sony MEXN5100BT (link at the bottom of this post). It features Pandora control, USB input, Siri Eyes Free (for apple iOS products), and is really easy to use and sounds good. With the USB input, you can even put a bunch of MP3 or other music files onto a tiny USB flash drive and leave it plugged in to the face plate all the time. It'll play them right off of the stick. It retails for $129.99 but I can buy it with my employee discount for you, which would make it $97.49 plus tax. Looks like we could get the necessary installation accessories for under $20 as well.
If you want to go that route, let me know. I can install it in my driveway for you in about 40 minutes, and remember that I'm just down the road in Murrieta.
Radio:
https://store.sony.com/receiver-w-bluetooth-nfc-app-remote-zid27-MEXN5100BT/cat-27-catid-all-car-stereo-receivers;pgid=vq1GmP9GBypSRpHag3jvgekR0000FVwqPpqK?_t=pfm%3Dsearch%26SearchTerm%3Dmexn5100bt