I wouldn't charge too much for teleport. If the fee is high then so few people will use it that it might as well not exist. I can go for charging 1 btcd for max security setting but if the coin reaches 10 dollars or more then sending just a simple transfer would be pricey at 1 btcd per low setting teleport.
Would it be possible to charge a percent of the market cap rather than a coin amount?
anything is possible, but querying orderbooks is not good design for this
also, it is not a fee, just a requirement to have some BTCD to be able to use teleport facilities
sort of like being part of the club.
James