I don't think that is a bad price for a scale that does all that. To convert grams to carats, just multiply x 5.
1 gram = 5 carats
1 carat = 0.2 grams.
From www.onlineconversions.com . Hope it helps. I may be worth the small price to pay for the scale if you are willing to do the math each time (or keep a cheat sheet) you need a conversion.
I have one of these and it works really well, also it is very sensitive so make sure your ceiling fan is turned off. If you search you can get one cheaper then this. Not that its that expensive as it is.
Go to a 'head shop', you know.. the places that pot smokers get their gear, and they'll generally have a whole whack of scales, electronic and otherwise. They'll often be priced lower too. ..Willy.
check out " myweigh" scales i have a durascale 50 and its very durable and has carats,grams.grains,dwt,mil.grams.it weighs up to 50 grams for about 50 bucks.they also have a durascale 100 that weighs up to 100 grams and is about 20 dollars more.plus they have a lifetime warranty.HH jeff