From your posts, I'm guessing that you want a digital piano (DP) rather than a keyboard. By DP, I mean an instrument with 88 hammer-action weighted keys. (As opposed to "keyboards" with lightly-weighted keys, usually fewer than 88.) Please forgive me if I guessed wrong.

There are several good entry-level DP's is your price range.

In slab pianos, the Casio PX-130 sells for $500. Personally I'd lean towards the PX-330 at $700 (but that's because I have my eye on one for use as a stage piano.) Yamaha's P-85 is $600. There should be good deals soon as the P-95 is coming out as replacement (summer, I think). Stretching a bit past $1000 is the Yamaha P-155. Keep in mind that stands and pedal units for all these models are an additional cost. And while all of these have internal speakers, they tend to be only 6-8 watts per side.

Sort-of-consoles (stand and pedals should be included): Check prices and spec sfor the newer Casio px-730 and px-830. Casios have come a long way in recent years. There are some complaints about keys becoming noisy after a few months but that problem may have been fixed in the x30 series.

Consoles (with furniture-style cabinets and pedals attached) are generally out of your price range but there are some good deals on about-to-be discontinued models. I teach one day per week at a Music and Arts store. I walked in last week and was astonished to see the YDP-223 reduced from $1600 to $1200. If you care a lot about specs, the YDP has only one sample layer. But I've been teaching on one for several years and I think it's fine. The speakers are 20 watts per side. It has Yamaha's better GH keyboard action (as does the P-155 slab piano).

Yamaha's YDP-140 used to be $1050. MAC is now selling it in stores for $800. Three sample layers but the speakers are only 6 watts per side. If you have good external speakers, the YDP-140 might be something to consider. BTW, Logitech Z-2300 2.1 computer speakers have something of a following as external speakers for home digital pianos.