It's worth whatever you can sell it for, and that varies considerably. I bought two treadle machines last year from craigslist for $50 and $45. One is a model 66 from 1911 and the other is a model 27. I passed up others in the same price range. I also saw one in an antique store for $395 in worse condition, and some of the ones on craigslist are asking ridiculous prices. The condition and type of decals influences the value, as does your geographic location, but there's still a very wide price range. A lot of these machines were made, and they didn't wear out quickly, so they're not that rare. I may be wrong, but I don't think the extra drawers in the cabinet will influence the price.