My son wants a tablet.......

Grab a used older version one from Craigslist? My Dad was selling his 1st gen iPad for $25 or something. 

We got a NextBook(?) at Wal-mart for a reasonable price. It would probably entertain an 8 year old for a while after you've downloaded some aps on it. It would keep the more expensive equipment from being beat up.

I like the Craigslist option mentioned above.

There are some incredibly inexpensive tablets out there.  It all depends upon what you're looking for in a tablet.

Do you need cellular data service (would require a data plan with your cell provider), or is WiFi good enough?

Does he need a large screen?  Do you think he needs Bluetooth connectivity?  How much does performance matter?

We just bought one for my girlfriend's 6 year old at HHGregg.  The brand is ProScan.  The speed of the hardware is somewhat lacking (older single core processor, not as much RAM as you might like to see otherwise, but acceptable) and also lacks Bluetooth, but it comes in a carrying case with a usb keyboard and it was only $70.  It is WiFi only, and has a 7" screen (which I think is plenty for smaller hands), and runs the latest non-KitKat version of the Android OS (4.2 JellyBean).  Literally, the only knock on the thing is the speed of the hardware... I've actually considered getting one for myself because it's simply all you really need.

Beyond that, we looked at the 7" Samsung Tab3 .  It's about twice the cost at $140, but it has much faster hardware and includes Bluetooth connectivity (good for wireless speakers, etc).  If we hadn't been buying for a 6 year old that was likely to lose or break the thing before it's a year old, this is the route we would have gone.

Google Nexus 7. My wife and I bought one before a road trip, $230 for the 16gb or $270 for the 32gb. It works great, never had a problem with it.

If he's anything like my niece, he just wants to play games. I would go the ebay/craigslist route and get whatever is cheapest. If he really exhibits a need for something with more capabilities, then you know and can do the real research.   My mom gave her old Kindle Fire to my niece and she loves it.  It would be useless to me.

If you have Amazon Prime account (or are willing to spend the $80 a year to get it), then a Kindle Fire is absolutely the way to go. Along with the apps, you can watch for free all of the movies and tv shows that are prime eligible on the Kindle.  It's usually not new releases, but they have a ton of stuff for kids.  You can download a free book once per month, and they recently added a streaming music thing, sort of like an ad-free Pandora.  

For the record, you can do this on any tablet if you have a Prime account, you just need to install the Amazon app (free).

I whole heartily support the notion of letting him spend his own money and then letting him be fully accountable and responsible for it.

Do they still make these?

Thanks for the input. Craigslist was also my first thought but he refused that idea. I tried to tell him his money would go a lot farther but you know how it is with kids, sometimes they just have to figure it out. He went shopping with DH today and they found a Kindle Fire at Best Buy for $119.