What 4 days? Depending on location Friday and Saturday nights can be really expensive. I just checked a spot I go now and then but not weekends and the closest Motel 6 was $135 a night, Friday and Saturday. Last year or before Covid anyways, $170 per night weekends. Buellton. OTOH. Lompoc only 17 or so miles away would be in the $50-$60 range, I think. Buellton is quite close to Solvang, has it's own restaurants, brewery and a few eating places. Solvang is quaint. Foody, winey - lots of vineyards and wineries in area. Santa Barbara probably close to or over $150 a night every night, weekends higher (Motel 6 is over $200 on weekends) 4 day averages would be lower, of course, but like he said. Need some help on what you might be interested in. Getting away from the beaches and especially popular or toney places will help on prices, of course.
Disneyland? Not as a recommendation but I don't know if will be open to out of state visitors. That might impact prices in the area. Seal Beach and south might be good to look at. Probably not price do-able in the beach towns, maybe. Depends on days and how close to the beach you actually get.
The greater L.A. area has maybe 12 million people here. depending on how you decide to count. A willingness to do some driving will help with things to do.