depending on what's covered

It's hard to determine whether it's a trap by price. You need to also look at what's included (meals, transportation, entrance fees, taxes, tips) and what type of hotels they put you in. Mid-level hotels in San Francisco start at about $130 (the likes of lower end hilton, marriott, etc), depending on the time of the year. Vegas hotels should be cheaper but again it's very seasonal. For that price, it's possible they put you in low end hotels at less desirable locations, the likes of Holiday Inn, Travel Lodge, Comfort Inn etc.