I don't think that the issue is the pricing spread on the formats for each title. Both CR and HM & MC: BoBWC on BD are priced at a "normal" BD release week pricing in the $24 - $28 range. What is really surprising is the SD-DVD release week pricing on HM & MC: BoBWC - I'm really surprised that none of the major retailers have it priced under $20. Considering the success of this title in theaters though, and Miley's live concerts, I'm guessing that Disney and the retailers believe that the demand by the teen / tween girls will be high enough that the higher than normal price won't be an issue. Then again, maybe the high SD-DVD price may be strategy by Disney to encourage people to spend a couple bucks more and step up to the BD format. Who knows???
Anyway, I bought both titles on SD-DVD because 1) they were cheaper, and 2) I only have one BD capable player (PS3) and numerous DVD players. Given the numerous viewings these titles are bound to see in my house, I didn't want to have a bottle-neck at the PS3.
I believe TRU is offering a 2/$40 deal if you buy the BD versions of HM and Camp Rock...so $30 if you redeem the Disney Movie Rewards $10 coupon. The following is YMMV, but there is a instant $10-off coupon on many--if not all--of the BD copies of Camp Rock (IIRC there is a similar instant-off coupon on the SD version of Camp Rock as well)...so if you can get a cashier to accept both the DMR and the instant-off coupons--hence the YMMV--you can possibly get both BD movies for $20 (plus tax, where applicable).