What's a camera similar to the nikon d3100 but cheaper?

My uncle has the nikon d3100 and I love it. Over the holidays I took about 400 pictures and I really enjoyed it. I found that many of my pictures were great even though I was an amateur and I got better the more I took. But I can't afford this camera. I want to know if there's anything really similar but much cheaper!

Since your uncle has Nikon, it would make more sense to go with Nikon than other brands

Currently, the Nikon D3100 is the cheapest in production DSLR right now. You can get a Nikon D3000, but the D3100 is much better.

save up and get it.

Well the quality you're looking for in a camera is really only found in DSLR's. Period.
Now, there are cheaper options.
The cameras I would recommend to you would be the Nikon D3000, or the Canon Rebel XS. They cost about $450 brand new, compared to the $600 D3100. But I would personally go on craigslist and find a used one for around $250-$300. Just search your local craigslist for one.

Any entry level DSLR from the past five years will give you great results compared to what you were used to. As others have said, you'll have to buy used to spend less than a D3100. The D40, D50, D60, D70, D80 are all $300 or less used and are very capable cameras. I would not go any older than these, though. My personal favorite in this batch is the D50.