Cryptopia just increased trading limit from 10 doge to 500 Doge, so I am in search of new trading exchange.
500 Doge is about 33000 satoshi which is the normal limit for trading volume that you can find elsewhere too. most exchanges have this limit at 10k-50k satoshi. in other words you won't find any better limits on other exchanges and if any one them have lower limits, they also will soon increase it due to Doge price drops and prevention of small orders filling the order book and wasting resources.
besides it doesn't make much sense to trade with such small amounts anyways!