This is odd for a transaction at this level, but not impossible.
Land Registry fee on transfer. €375. Fee on Mortgage (if there is one) €125. Fee on Subdivision (if this is a new house) €60. Fee on copy folio and map €25. Fee on cert. of charge\counterpart mortgage €6. Total €591.
Other possible outlays include €25 on each land registry discharge of a prior mortgage (if any) though these would normally be paid by the vendor. However, if they were not, for some reason, paid, then they might have made their way onto the bill.
Finally, you could have a mixed title - partly Land Registry and partly Registry of Deeds - in which case two sets of registration fees would be incurred. i.e. as per above plus an additional circa €100 - €132. The high search fees of €300 would be consistent with having two do searches on two titles. But the round sum is odd, unless the original poster was simply rounding off when giving details.
In short, it is unlikely, but possible, that the registration fee could have reached close to €800
The Land Registry do not give receipts, but it is still a simple matter to ask what was actually incurred and be given detailed particulars. Most solicitors would itemise the costs on their bill.