Yes.
The tickets should have the value of the same sort of ticket pre-purchased from
disneyland.com. While WDW doesn't discount ticket-only purchases, DLR does, so if you check out the normal pre-purchase deal online (not a special like 5 for 3, or everyone pays kid's price, etc) that should be what your tickets are valued at.
Then you take the cost of the AP and subtract the value, and that's what you pay.
At WDW they "bridge" the price, but at DLR you don't, so the value of the ticket is the value of the ticket.
When we went, our adult tickets were valued at something like 189. The APs our first time were 239, or something like that. The adults each paid $50, DS paid more b/c APs are all the same cost, but his ticket was valued as less.
Be sure to watch out for blockout days; you can upgrade ON a blockout day and stay at the park (and hop and all), but you do not want to upgrade *before* a blockout day during your trip, if you're planning on going to the parks on that blockout day.