I highly recommend getting a referral from someone in your local area who has used, and is satisfied with, an estate planning attorney (one whom you can use for years down the road in the eventuality of any changes or further amendments).
For a simple amendment, you might pay anywhere from $400 to over $1,000 (whereas a complete individual living trust would run $1,000 to $1,500 and a joint trust over $2,000). Note that the aforementioned are not "cookie cutter" trusts, which is what you do not want (standard, plain vanilla, one-size-fits-all language); you want a document drafted for your specific situation and circumstances.
