I need some additional opinions on my bike gearing situation.

I have a new (2007) cross bike with a compact double on the front (38/46T) and a 10-speed cassette (12-27) (additional specs here). I'd really like to have some much lower gearing for those climbing big, steep hills that I'm inexplicably attracted to. I seem to have a couple options:

1. Convert to a triple and get a nice low granny gear.
2. Convert the rear derailleur to a mtb one and put a mtb-geared cassette on there.
3. Get a smaller small chainring.

When I talked to my LBS, they said:
1. Converting to a triple will cost like $500 -- about 1/3 the total cost of the bike. Ick. They said I didn't have a compact on my bike right now, which confused me, because I really thought I did.
2. Converting to mtb stuff on the rear will also be expensive, because there aren't any 10-speed mtb cassettes. I'd have to get a new shifter, etc. to accommodate a 9-speed cassette.
3. There aren't smaller small chainrings that would fit on my bike.

I very recently replaced my cassette and chainrings, so I'm kind of reluctant to make any major changes this go-round, but for the next time everything wears out, what are other options I might have?