I'm a direct owner of Riviera.
For a prospective re-sale buyer,my questions and advice would be:
-- Is Riviera your favorite
DVC property? If not, no reason to consider it, at pretty much any price.
Assuming Riviera is your favorite property:
-- Do you travel during high demand times of year? If so, availability is limited outside of your home resort anyway. There isn't much downside to the resale restrictions. You'd basically be stuck at your home resort regardless. So why not consider paying market price for your preferred resort.
--Even if Riviera is your favorite, by how much? Are there other resorts that you love just as much, and you'd want to do different resorts every year? Then again, Riviera probably isn't for you -- Though maybe for the right price, you'd be willing to sacrifice the ability to trade to other resorts. So, if BLT (for example) was $170 per point... Would you be willing to trade away the other resorts for a nice discount, down to $150 per point?
--Now, speaking for my own family -- Is your Riviera preference strong enough that you really don't think you're missing out if you can't really stay at the other resorts? If so, then go buy Riviera at market price.