Sorry I know this isn't technical so to speak but I have recently been asked to take over a customers database in terms of support & changes from another developer who has lost interest.
Im cautious taking over a client like this but in the real life it has to happen sometimes and I'm trying to not lose my shirt on this one!!.
Im not asking anyone to price such things but merely some advice on how others approach their pricing strategy on this one.
The safest option is to say that it will cost so much a day and I have no idea how long it will take, nice.. but in business rarely washes with a client.
I am considering pitching a Maintenance fee on it per year and that would give me some cushion, wiggle room if some development got out of hand.
I would class this as a basic, smallish application.