If the house is an old one, it is likely that it is a "Registry of Deeds" title. This means that the registration fee for the conveyance (transfer) is €44.00 and the same again for the mortgage.
If it changed hands last year, the relatively recent Registry of Deeds searches should be with the title documents and need only small updating (at minimal cost). Other searches ( e.g. Judgment and Bankruptcy ) would still be needed, but the cost of searches would be relatively modest - less than €50.00. Commissioners fees would be €20-€30.
So, although the figure of under €100 is a touch optimistic, it is possible to have relatively small outlays only slightly over €100.00, depending upon the circumstances of the individual title.
No matter who you go to, the outlays should reflect the money actually spent, except for the catch-all "petty outlays" figure. Also, some solicitors avail of a "flat rate" searches service, so that the client knows beforehand exactly what such a service will cost. In this example, you would lose out by your solicitor using a flat rate law searcher, but it is the nature of such a service that a solicitor either uses a flat rate for all transactions or gets individually billed by the law searchers for all transactions - it is not possible for the solicityor to cherry pick.