Ok, I built an arena for you, some what. I LOVE barn management and construction, so I liked doing this.
For a correctly built arena it's very difficult to build under 1,000. I'm not including labor and machine rental with these figures. But, it's close to possible to build a nice arena that will last if it's carefully thought out.
The size I went with was 50x70 feet. I'm not sure if you're crazy about this size. Any bigger and I couldn't fit it in your price range from the prices I saw. If you want a specific size, I can calculate it for you.
So, 50x70 equals 3,500 sq ft.
For the footing I found a website (
wcfootings.com) that had recycled tire-like material for footing. I enjoy this footing when it is mixed with something harder so it isn't like a trampoline. The footing cost:
1.50 lb/sq ft at $0.25/pound which equals $291.00 for 1750 sq ft. Notice I cut the total square feet of the arena in half because I mixed the footing with a cheaper material - sand.
So, with that said,
Sand covered 100 sq ft /ton on an online conversation chart. Therefore you'd need 17.5 tons of sand which I found sand at about $8.50 - $15 per ton, so I said $10/ton to be safe. Sand totaled about $170.00 for the other half of the arena.
Layers need to be built under the footing to protect from rain and weather. A strong filter fabric made for arenas should be about $0.10/sq ft, totaling $350.00.
Your sub-base is the most important part. Compacting it is key and the thicker, the better. (Up until about 18 inches.) But, you do what you can!
For gravel it totaled about $0.05/ sq ft. This equaled $175 and was doubled to get 2 inches depth. Deeper would be ideal. If you could go without fencing, I'd buy more gravel. This over all totaled $350.00.
And to fencing. I used 1inch 8ft x 12ft wood (priced online from home depot) for about $11/board. You have a 114ft fence to build around this size arena (making room for a 6 foot entrance). So, these estimates are for a fence with 2 rows of wood going horizontally. Like this but of course, nice flat wood:
It would require 20 boards horizontally and 10 boards vertically to make your post. The post would be placed every 6 feet apart. The top of the fence would stand 5 feet high assuming you post goes 1 foot into the ground. The 10 boards would be cut in half to make the post. (saving you from buying 20 post instead) The fencing for two rows horizontally equals 330.00. For just a single row horizontally, it would cost 220.00. The fence could be done in numerous ways, this is just a basic idea.
Total for everything plus a double fence: 1491.50
Total for everything plus a single fence: 1381.50
My calculations may have mistakes somewhere, so sorry if they do! And of course, I'm sure prices vary but this gives you some what of an idea.