This deal (Boardwalk Inn for around $200 a night) is still available (as of this posting), but there is a *trick* to getting it to appear. I'll do my best to explain the process I use.
1. Use the Priceline desktop site - this has not worked on the mobile site or their app.
2. I use Chrome as my browser, but this is not a deal breaker.
3. Type in these dates June 30th - July 7th for the location Lake Buena Vista
4. Once you get the results, click Express Deals near the top right of the screen
5. Filter to 4* and the area of Bonnet Creek
6. As of this posting, you may see a hotel selection for $130 (this is NOT a Disney Hotel)
7. But, still click the "Choose" button for that 4* in Bonnet Creek. It should open up a new tab...
Here is the trick...
8. Click on the tab you just came from (don't click the back button)
9. From here, you may see additional blinded 4* hotel selections in the same Bonnet Creek area. As of this posting I am seeing 3 additional hotels available and I believe they are Boardwalk (9+ at $210ish, AKL 8+ at $230ish and Dolphin (7+ at $145ish). These are my best guesses on the hotels, please do not hold me liable
Also, baler31 is correct that clearing your cache and cookies every now and then may result in updated results and/or better pricing.
I hope that makes sense and allows you to see more Express Deal choices than what's first displayed. This trick doesn't always work (I guess it's based on their inventory), but it works a fair amount of the time.