I've done exactly this for the last few years. I have a bunch of text files with likes like # 3rd (of march) mail 2.23 mailing for bookmooch lunch

I've done exactly this for the last few years. I have a bunch of text files with likes like # 3rd (of march) mail 2.23 mailing for bookmooch lunch 6.04 soup and sandwich @ riverfront cafe espresso 1.29 # 4th groc 29.57 groc run etc. I was previously totaling it with a short Python script, but now I'm using a tiny awk script (it's exactly the sort of thing it was designed for). Either way, it's incredibly easy to parse simple text files like that, dump the results out to gnuplot, etc. Just plugging in receipts once every week or two doesn't take very long.