Well, inexpensive is a pretty relative term, but I usually use the Hotel section of the Orlando 411 Internet Directory. I looked for you and the one I like best that has a GREAT price now is..
The Buena Vista Palace Hotel & Spa
4 out of 5 Star Rating
1900 N Buena Vista Dr
Lake Buena Vista, FL 32830
The prices listed was only $93 a night and normal price for this one is $200-$300 a night there was nothing even close for price for something this nice. If you want something a lot cheaper they will have it but make sure to read the reviews.
Otown411 Directory Hotels Section http://www.otown411.com/Orlando_Visitors...
Click the link at top of page for Booking Best Deals...
Choose Orlando and your dates. If your lucky the one at Buena Vista Palace is still available, there were some places for around $50 a night but read the reviews.
edit: Found another great deal for you via Otown411.com they are only $79 a night have a 30% savings on top of the normal discount via Otown411.com
Wyndham Orlando Resort
3.5 out of 5 Star Rating
8001 International Dr
Orlando, FL 32819