Hi Aleksander,
Technical things are important too.
From my experience I can tell you that prepearing your photos by yourself ends with a disaster.
You need special equipement and a lot of experience in doing that.
Everything what you need in size 24×30 cm would cost about 6€.
Here I send you a link to a laboratory where I print my photos: http://www.fotonet.info/index.php?&action=c_powiekszenia
You can also add frames but it would be more expensive.
I suggest doing passe-partout together with a photo, here come my exapmles