TJ has lots of "short-time" motels.  (The reason is young couples have trouble finding privacy, plus, of course, lots of locals cheat on their wives.)  La Mansion is the best known among mongers, but such places are located  throughout Tijuana.  (Some, like Premier, I prefer to La Mansion.)

Basic rooms are usually $35-$40.  Jacuzzi rooms are around $65.00+.

Most places don't allow "in & out" privileges.  (Use El Parador for that.)  Also when busy (like on weekends) the stay is often limited to 4 hours.

$36 regular room, yours for the night Sunday - Thursday, Fri & Sat, room is yours for 3hrs only for that same price.
$61 for Jacuzzi room, same above rules apply.
Considering the value you'll get in return, those are great rates; the catch here is that once you leave that room for whatever reason, you loose it.