Spent all your cash on girlie drinks and shattered dreams again this weekend, didn't you? No worries - Thriftster gives you the lowdown on cheap stuff to do until Paycheck Friday. Monday: Start the week out on a socially responsible note with the Houston Grand Opera at the Museum of Fine Arts Brown Auditorium (1001 Bissonnet St.). The event is honoring writer Leah Lax and who interviewed hundreds of Houston immigrants from around the globe......