It would, of course, very much depend on the quality of furniture you want. For example, we had a pack for our first flat which consisted of bed settee, 1 double and 2 single beds, coffee table, display cabinet and tv stand, bedding, all the cutlery and crockery you could want for six people, an electric oven and hob , curtains, lights and so on. All for €650. Obviously, not the best stuff in the world for that price but you get what you pay for. The company we use, Arca, did packs from that price up to about €4,000 and you had a choice of types of wood etc. For our house, we didn't use a pack but bought items separately.
When we first lived near Malaga, our neighbours used this company for furniture packs and were very pleased with them. I seem to remember the pack they chose was about €8,000 and the company did everything, hung curtains, put beds together and unpacked everything. However, that was about 6 years so can't vouch for the prices.
It would probably be a good idea to get a basic pack so everything is there if you are using it as a holiday home. But if you want to change it all later, it would't be a good idea to get a more expensive one unless you have a free choice on what you actually want.
The price of €40,000 extra if it is furnished is obviously OTT unless it includes mahoosive TV, fully fitted aircon, heating, decent white goods and so on. Also, new and unfurnished houses may not have any light fittings (just bare wires sticking out all over the place) and landscaped gardens whereas the furnished one might. Our costs for the aircon and heating came to €3,000, the tiling and landscaping of front garden and steps etc about the same. The white goods with decent fridge/freezer, oven, ceramic hob, dishwasher, washing machine and things like a toaster and kettle came to around €2,000. A lot for you to think about.