The biggest one involves relying on the seller's lawyer. The seller gets a commission on completion, which is not the same as protecting the buyer. Your own legal adviser represents a small fraction of the purchase and remains the best protection.
Signing in a language you do not speak comes a close second. A sworn translation costs little next to the purchase price. Assurances given by the agent mean nothing if the written contract says otherwise — only the signed text matters.
Committing to an unbuilt project blindly has ruined plenty of plans. Ahead of a deposit, look at the developer's completed projects, the building permits, and whether payments are held in escrow. Projects running behind schedule are normal with even the best developers; abandoned sites are the exception but genuinely ruinous.
Forgetting about resale is less obvious but just as costly. Every purchase has to be sold or passed on at some point, and the pool of future buyers matters. A unit that only appeals to foreign buyers sells slowly when conditions change.
Lastly, a lot of buyers underestimate the ongoing obligations. Tax filings can be required even villas for sale in larnaca years with no rental income, buy a home in arapkoy and overlooked notices generate charges nobody warns you about. Putting land for sale in limassol place a local tax adviser at the outset heads off most of it.