Keep in mind, you may do better off if you can find a broker that still has "old stock" tickets. Meaning from before the price increase last week.
Example, a 3 day MYW base ticket lists at $238.56, no hopping, no plus, expires in 14 days. Even if Expedia give you a free upgrade to a 7 day MYW base ticket, that only has a current value of $263.06. A 7 day MYW no expire costs $414.29, so you would have to pay $151.23 (assuming you upgrade after using at least 1 day) This means you would end up paying $238.56 + $151.23 out of pocket, which is $389.79. Currently, Undercover Tourist still have a 7 day MYW no expire listed at $355.95, which is a savings of $33.84 off of the upgraded Expedia tickets. Now if Expedia is offering a discount in addition to the upgrade, then it may be worth it. But the only tickets I can find on Expedia are at WDW list prices. Keep in mind that Undercover Tourist or any other broker could run out of old stock tickets at any time so the savings may be less or non existent depending on the current prices.
That said, as a PP said, non expire tickets may not always be best depending on the length of you next trip. If you need to buy a second ticket in addition to your remaining non expire tickets, it may cost you more than just using the 3 days now, and then buying a ticket specifically your next trip. Do the math and see what works best.
Example, say you went for 3 days now, and a week in April. A 7 day non expire now (from your Expedia deal and upgraded), plus a 3 day expire then would cost 652.85, while a 3 day expire and a 7 day expire costs 501.62, while a 10 day no expire is 505.88 (all based off list price) A big non expiring ticket tends to work out well if you usually do 3-4 days trips. Case in point, I bought one for my wife as she would only do 3 or 4 park days during a trip. So we would get 3 trips out of that 10 day non expire at 505.88. If we had bought base tickets, the same 10 days would have cost us 724.20. So there it made sense. Run the numbers and see what works for you.
