Another Spaniard here. I've been following prices of the N9 in Europe (you'll get a EU guarantee with them) and I'd say the best place to find them is at Geizhals:

64GB: http://geizhals.at/eu/654041
16GB black: http://geizhals.at/eu/654017
16GB magenta: http://geizhals.at/eu/654049
16GB cyan: http://geizhals.at/eu/654042

Don't get too excited with the Polish prices. I've never found a Polish reseller willing to ship abroad. German stores, on the contrary, are always happy to ship to Spain. If you can buy as a company, you may skip the VAT too...

Good luck.

PS: Maybe there are some Polish TMO members around? They might help with the 16GB black model...