The most expensive mistake involves relying on the seller's lawyer. The seller earns money when the deal closes, which is a different interest than protecting the buyer. An independent lawyer costs a fraction of what is at stake and is the single best safeguard.
Signing documents you cannot read comes a close second. An official translation is inexpensive set against the purchase price. Assurances given by the agent will not help if the written contract says otherwise — the contract is what counts.
Committing to an unbuilt project blindly has ruined a great many buyers. Ahead of a deposit, look at what the company has already delivered, the building permits, topla real estate and whether payments are held in escrow. Projects running behind schedule are normal with even the best developers; abandoned sites are rarer but much more damaging.
Thinking only about the purchase is a subtler error. Any property will one day be sold, blanes villas and the resale market matters. A property with no local demand sells slowly when sentiment turns.
Lastly, many buyers misjudge the running costs. Tax filings are often required regardless of whether the property earns anything, and late filings attract penalties that accumulate quietly. Putting in place a local tax adviser from the start heads off the majority of these headaches.