There are a lot of discussions related to tickets and discounted tickets in the Theme Parks Attractions and Strategies Forum. You will find that there are several "authorized resellers" who can give discounts, generally not much more than five percent, from the gate prices.
Be aware of the regular pricing. Disney Park tickets are "front-loaded". For an adult, for example, the first day is $82 (plus tax), the second is $80, the third is $62, the fourth is $8 and days five thru ten are only $5 each.
Avoid any time share places like the plague, they are high pressure, they lie, and any tickets you get from them cannot be upgraded or modified in any way.
Do not, under any circumstance, buy tickets from eBay or Craigslist or any other online source unless you personally know the seller. There is absolutely no way, looking at a Disney ticket, can you actaully tell what is on the ticket.
You might want to look at the Everything About WDW Tickets locked sticky in the TPA&S Forum. Especially the items bolded in the list below.
Post and Contents
1. This Table of Contents
2. Magic Your Way (MYW) Ticket Basics Including Definitions
3. Annual Passes and Water Park Tickets
4. Tickets Available Only to Florida Residents
5. Tickets Not Available to the General Public
6. Upgrading MYW Tickets (Not to Annual Passes)
7. Upgrading Tickets to Annual Passes
8. Dealing With Tickets Issued Prior to 1 January 2005 (Pre-MYW)
9. Children and Adults
10. Special Events
11. Comprehensive MYW Ticket Example
12. Hotel Card (Key To The World (KTTW))
13. Lost Tickets
14. Finger Scans
15. Frequently Asked Ticket Questions.
15A. Hopping Rules
15B. WPF&M With No Expire
15C. No Expire Upgrades
15D. Upgrading an Unused Ticket
15E. Upgrading Special Tickets
15F. Checking on Old Tickets
15G. Renewing Annual Passes
15H. Upgrading a Completely Used Ticket
15I. Getting Park Tickets Before Package Start Date
16. Resident 4 Day Wild 4 Disney Pass
17. 2010/2011 Armed Forces Salute Tickets
18. Prices Effective August 5, 2010
19. "Free" Tickets and Special Promotions
20. Ticket Purchase/Upgrade Locations and Telephones
21. Florida Resident Installment Purchases of Annual Passes
To get there directly, follow the link in my signature.