We found Anegada relatively inexpensive, with the exception of 'creative fees' at the Anegada reef hotel. They charge extra for just about anything.
The bakery was great and inexpensive, northside restaurants excellent and also inexpensive, rental from Anegada Reef was prohibitive, but from DW rentals surprisingly cheap. Flights are set up so you can reach the place in a day through san juan.
House rental was very reasonable. Provisioning the houseis hard and can get costly. See if the house renter can provision the house with a list you supply - it worked out for us. There's is very little available on the island for sale. People are very nice and helpful.
p.m. if you'd like more detailed info.