Thanks for the advice, I didn't realise that opportunities can come around if you don't complete them. I'll definitely hang onto the relic!
I've already had a stripped dressed person come round to try and steal something. They walked right past my Tombs of Egypt relic collection and stole the virtual goggles. My sims got the Brave trait so she was all up for fighting the robber. The police came over, and lost in the fight with the robber, after which I got the sorry, he's gotten away message. My sim wouldn't have any of it and went and fought the robber, in her nightie! And she won! I was like wow, you go girl. After which I couldn't believe it when the policewomen (who witnessed the fight) just looked at the robber and calmly walked out! Closely followed by the robber! Go figure!
I also wanted to say I love this forum, and Carl's advice pages. I pretty much check it everyday. At some point I'll upload an avatar, once I have the patience to make a sim look kinda like me in CAS.