My concern is that when they do announce the price, and will be a best guess, nothing definitive, if some will say "Not worth it" and cancel their order.
I'm on the fence there myself.
Here is Slate's 'official' position on price (from Slate.Auto):
We’re committed to keeping the price for the Blank Slate in the mid-twenties, which is what we announced when we revealed Slate.
We said it, we meant it, we’re sticking to it.
Pricing for the Blank Slate and several key accessories will be announced in late June.
Pricing to be revealed on 'several' (not all) key accessories, likely to include the SUV / Cargo kits, larger battery, some wraps, and perhaps the roof rack, spare tire carrier, bumpers and wheel kits. Pure speculation.