From the sticky threads at the top of the first page, some threads with good information for you:
A DLR Guide for WDW Vets
"HydroGuy's Hotel Rule"
www.disboards.com/showthread.php?t=1199862
"Choosing the Right DLR Area Hotel for You"
www.disboards.com/threads/choosing-the-right-hotel-for-you.3656512/
Less than $300/night should definitely be doable. I'd skip the Clarion (friends stayed once and said never again). The suggestions for the Motel 6, Hotel Indigo, Candy Cane Inn (we stay here in the Premium Rooms -- well under $300/nt. -- breakfast delivered to the room! -- always clean, private shuttle, great customer service, return customer discount if you decide to return with the kids), Kings Inn, DI&S are good. Also look at the Majestic Garden (private shuttle and walking distance to the M&F tram), the Hilton (often has specials), and any hotels near the TS lot (use Google maps to see which hotels are walking distance to that lot). You can walk to TS and use the free shuttles to/from the parks. If you are open to using Uber/Lyft, look in Garden Grove for lower hotel rates -- some hotels are only one mile south of the parks on Harbor, like the Embassy Suites, Hilton Garden Inn, Hampton Inn & Suites, Hyatt OC, etc.
Check the websites of each hotel and if you find a great rate with a no penalty cancellation policy, book it. Then call the hotel directly to see if the front desk (not the 800 number) can beat that rate.
Book your tickets separately -- there are authorized discount vendors that are used by many on this board. Check Mousesavers.com for offers that cover your dates -- all vendors listed there are legit. People here use: AAA, Costco (for packages), aRes, Getawaytoday, UT, and LMT (this site is undergoing some work right now).