In Spain the printing is cheap. The paperwork is the expensive part.

PLA lands at roughly 15 to 22 euros a kilo delivered from the Spanish and EU sellers, so 1.5 to 2.2 cents a gram. A 70 g print is about 1.05 to 1.55 euros of plastic.

Spanish household electricity sits below the EU average, and the gap with a German or Irish printer is real money over a year of long prints. A five-hour print at 120 W is 0.6 kWh — somewhere around 12 to 18 cents on most Spanish tariffs.

If you are on a time-of-use tariff, and most Spanish households are, start long prints in the cheap hours. Nothing else in this guide will cut your running costs by as much for as little effort.

Eurostat put the EU average household electricity price at about 29 cents a kilowatt hour in the second half of 2025, with Ireland and Germany highest at roughly 40 and 39. Your own tariff is the only one that matters, so take it off your bill, or put a 10-euro plug meter on the printer for a week.

Correos is the default and rarely the cheapest. The courier comparison sites, booking SEUR, GLS or MRW for you, usually beat the counter price for a small parcel, and dropping at a parcel point beats collection.

• Peninsular and not. The Balearics, the Canaries, Ceuta and Melilla are priced differently, and the Canaries involve customs. Quote them separately or say you do not post there.
• Design for the smallest tier. The jump between size bands costs more than most prints are worth.
• Collection beats the Post Office queue once you are sending more than a couple a week.

Spain has no comfortable small-earnings allowance of the kind Britain and Germany have. Selling as a habitual activity means registering with Hacienda and with social security as autónomo, and the social security cuota is monthly whether you sold anything that month or not.

What softens it is the tarifa plana for new freelancers: about 80 euros a month, nearer 87.80 with the MEI surcharge, for the first twelve months, with 2026 rates frozen at 2025 levels. That is roughly 1,050 euros across a first year before income tax, which is the number your side income has to clear before it is worth anything.

Which is why in Spain, more than anywhere else in this series, a handful of cheap printed novelties is not a business. Work out what the year costs you first, then decide what you need to charge. Figures checked in October 2026; confirm with Seguridad Social and the Agencia Tributaria, and talk to a gestor.

Wallapop and Milanuncios carry the casual local trade; Etsy and Amazon reach beyond Spain but bring you into the same crowded categories as everyone else. The reliable money is the same as everywhere: businesses. Hospitality fittings, replacement parts for machines nobody supports, signage, prototype parts for small workshops.

Spain's seasonal tourist economy is worth a thought: bars, beach clubs and hotels replace small broken fittings constantly and will pay for same-week. That is work no marketplace seller can take from you. The filter is in what actually sells.