Well how much money you spend at each and thus the relative cost of each depends upon a lot of things.
1. Where you stay
If you insist on staying at a Disney Property well there is no way around the fact that there are no values or moderates at DLR like at WDW. So DLR will be more expensive. But if you stay in some of the more expensive deluxe rooms at WDW, those are more expensive than anything DLR has. Also, outside hotels are just a 5 minute walk away at DLR. If you stay in one of those, you can get at or near (sometimes better) than WDW's value price.
2. Tickets are priced at each so staying more days brings the additional cost of each day eventually down to near nothing. I think it was $2 to add an 8th day onto each ticket at WDW. So 10 days there isn't much more than 5 in the way of ticket prices. DLR isn't a 10 day destination so you can't take advantage of that.
3. Food. WDW has the meal plan. And if you like sit downs, this can save you a lot of money vs the sit downs at DLR. But in both cases, if you don't need or want sit downs, you're better off not getting the plan at WDW and going to the counters. But counter prices are nearly the same. But off site options are much more viable at DLR than they are at WDW and that can save you a bit of money. And if you don't have a car at WDW, you can virtually forget eating meals off site.
4. Air fare. This is a large chunk of a trip price. If you can drive to one but not the other, well 9 times out of 10, the one you can drive is going to be cheaper. Also, a cross country airfare is usually more expensive than an in-region one. But not always.
5. If you pick the right hotel, you won't need a rental car at DLR. You won't need one at WDW either but many people are more likely to want one for convenience at WDW.
6. There is nothing you can do at WDW in 3-4 days that will have more fun packed into it than 3-4 days at DLR. It is only over longer trips where the advantages of WDW over DLR come out. Let me put this a different way. There are almost as many attractions at DLR's 2 parks as there are in WDW's 4. But WDW involves so much walking, you can't get to em all in 3-4 days at WDW. You can indeed get to em all in DLR especially since it's open longer on average. Plus, Disneyland time is BEHIND most of the continental United States. Disneyworld time is AHEAD of most of the continental United States
That makes it far easier for many to get up early and get to the parks at their least crowded at DLR.
7. Deals. At WDW, they usually offer things like free hopping plus water fun packs. They also usually offer deep discounts at the hotels for AP holders. Also, they've offered free food at WDW. If you stay value hotel or mod, there is no topping that. That's a big chunk of expense wiped off right there.
As I tend to stay off-site at DLR, I can't really take advantage of any hotel deal at dlr like 4 nights for 3. Deals can and do occur at the outside hotels too. But you have to keep looking.
Because there are 5 airports in range in LA and only 1 in Orlando (2 if you count Tampa but you'd have to rent a car from there.) I can usually get some discounted deals to at least one of them in LA, whereas I can't get that as readily to Orlando.
Enjoy it especially since you know you won't be taking some big trips for awhile!
