There are a number of condos in Princeville, which many people love.

Personally my favorite place would be Hanalei Colony Resort http://www.hcr.com It is more expensive than the price range you gave, but it is true beachfront as you can see here http://www.hawaiirevealed.com/free-travel-info/kauai/kauai-resorts/haena-area/hanalei-colony-resort
The most affordable units, the garden view, really do not have an ocean view from the rooms, but once you step outside you are just feet from the ocean.

There are also rentals in the Ha'ena area, and in Hanalei. Have you checked VRBO?

There are many condos available in Kauai, I hope this link would help you to find a suitable condo for you.
http://www.alohacondos.com/kauai

The Hanalei Colony resort is indeed beautiful - and we enjoyed a beachfront unit during our Honeymoon back in '86. Charo even had her restaurant going then - and we enjoyed meeting her. Gucci Gucci and all that. http://www.tripadvisor.in/ShowTopic-g29218-i304-k154631-Whatever_Happened_to_Charo_s_Resturant-Kauai_Hawaii.html

It's now a different - but still very good restaurant, and I believe they have a good luau there from time to time.

If you want something that might be less expensive - at our timeshare place - the Cliffs Club - http://www.cliffsatprinceville.com/ - they also rent out condos - and if you get one in building 8 or 9 - you can have both an ocean and mountain view. While you don't have ready beach access, you are not that far from several nice beaches.

We have actually hiked down the trial from the Cliffs to the ocean/reefs below - but not sure it's open any more - as it could get a bit tricky.

And as noted above - there are other condos for rent in the Princeville area - which again - sit above the ocean on a cliff - with beautiful views of the blue Pacific.

Forgot to mention. If you check the weekly rates for condos - you usually get a better deal.

Many of the Sealodge condos have oceanfront views--and mountain views from the kitchen. But Sealodge beach is a trek down a trail. I drive the 10 minutes to Anini or Hanalei Beach for the closest beaches without a hike.

Pali Ke Kua has some gorgeous ocean views with Bali Hai in the distance. It's walking distance to the beach at the St. Regis (which is public--like all Hawaii beaches). There's also a trail right there, but again, it's another steep trek. Princeville is high on a bluff--so nothing sits right on a beach there. I liked that when there was a tsunami alert .

North Shore, Hanalei Bay Resort, but only rent through an owner, as the complaints on TripAdviser are all for the hotel and timeshare units, which they are starting construction on. Try for something in the 4000 building for both ocean and Bali Hai views. Beautiful pools and if you do not to walk back up, they will send a golf cart for you.