Having heard this more than once now, I think it’s time to speak out.
DSLRs and mirrorless both have their entry level price point at around $300 – that gets you a Pentax K-X0 or an Olympus E-PMY, for some value of X and Y corresponding to the current generation of camera systems. Then you have a typical enthusiast/semi-pro camera around $1000 body-only, and finally you might have a full-frame pro camera that’s $2k-$2.5k.
Now, that just gets you a camera, not a system. You also need some lenses. Let’s assume you want autofocus. Then you can forget about adapting DSLR lenses on a mirrorless system. You have to buy native. Well, native lenses haven’t been around for long, so there won’t be a real bargain on eBay yet for your mirrorless system. Likely you’ll have to buy new and pay in the region of $400-800 per lens, maybe more, depending on your needs. Well, for a DSLR camera, you may be able to buy a good used copy, and pay three quarters or even half, if you’re lucky, of the current new price. However, when you factor in that some DSLR lenses have been on the market for a while, allowing for new prices to also slide, you have quite a compelling value proposition on the DSLR side.
If you want a budget system, don’t buy mirrorless, or be very sure that you know exactly what you’re doing!