North or South Salinas? The Motel 6 in south Salinas is in a relatively quiet part of town by the airport with relatively easy freeway access to HW 68 and Monterey - if tourist season is out of control in Monterey, this is my last option, but a decent one. Just be sure to bring extra pillows and some decent towels.
I won't stay in the North Salinas Motel 6.
In my opinion, when shopping for hotels on the Monterey peninsula,
www.orbitz.com is your friend. I've been coming from three hours away to dive Monterey for many years and I've never found one place that consistently reasonable, all the time, hence the need for Orbitz. The Carmel Hill Lodge on Munras, just across from the Del Monte Shopping center however, is usually available midweek and during off months for 40-60 per night. I've been using them for the last few months on my dive weekends, but they're about to triple their rates, along with seemingly every other hotel in Monterey-Pacific Grove-Carmel as tourist season begins.
Happy hunting!