No dais might not cut it, but that may be the route they go just so that most people could afford it.
If a basic figure is $20, what's a speederbike plus figure gonna cost? $40-50? What retail store is going to carry a $50 6" set in this market? TRU maybe?
And what'll happen with Jabba? If he's in the same assortment as the Speederbike, then that means a $40-50 Jabba without dais. What would it cost with a full dais? The walmart 3.75" set was what, $40? Does that mean a 6" Jabba with throne would be priced at $80? I can hear the outrage now...
The first problem is that the 6" figures are over priced by about $5 right now. If they want people to adopt the line, they need to bring it down a little bit... $17.99 even.
Second, yeah - Jabba with a Dias would probably be expensive. At least $60. I bet it would sell like gang busters though. I think the 6" line is more collector driven than kid driven at this point and collectors would gobble that up.
Parents wander in and there is a 18 year history of 3 3/4" figures with lots to choose from ranging in price from $5.99 to $9.99 - most parents (unless the kid really really wants it) aren't going to ditch all that for a $20 figure especially with so few to choose from. And, with waves of four every couple of months, it's not like there's going to be a day any time soon where there are more than 4 or 8 options to buy from at a given time.
Are kids freaking out demanding the larger scale? I don't know, but given that pretty much only Artoo is on the shelves, I doubt it.