No, it was not easy to foresee Sandoval being a bust, at least not in the first part of his contract. Dude was 28 when he signed his contract. It was reasonable to expect a mild dropoff, which would still be an improvement over what we had the previous year. It was not reasonable to expect anywhere near the disaster that we saw.
Was Pablo more of a risk to be a bust than Price in the early part of the contracts? Absolutely. But again, Pablo's contract is not nearly large as Price's.
Also, I will say again that I am not a fan of Pablo's contract. I would have preferred Headley myself. However, the aggregrate offensive runs above average provided by the 3B in 2014 was -27.4. Their defense was -5.3 runs. Clearly, we needed an upgrade at that position, particularly offensively, which Pablo should have provided. The FO signed the best (or one of the best) free agents to fill that hole. Isn't that what fans are always clamoring for?