For a stage payment mortgage, we charge from a minimum of €1000 (plus VAT and outlay) to a max of perhaps €1800. We don't set a fixed fee in advance, because self builds are too variable in terms of the work required. Nor do we ever fall out with clients over money - by the time you are at the last or second last payment, the client has an appreciation of the work that has gone in.
The stage payment mortgage is not very profitable work for a solicitor - I know some solicitors who simply decline to take on stage payment mortgage work. We would charge more, but it is a rural practice where we would usually have already acted in relation to a family site transfer, and perhaps have a lot of the family as clients, so there is an element of having to meet client expectations and hoping you might make it back on some other business. Frankly, if your solicitor does not have any such incentive to go light on fees, you could easily be paying €2k.