I went over all of the maps and stuffs, and i cam not seeing anything that you 'build up' or upgrade in any way. Nor is tere anything like that in MM1, ( dont make me actually go look, that game was.. a bit painful, and not advanced enough to allow for a turnip to be upgraded
First time you could get a castle of yoru own was in mm4 when you could buy a desroyed castle and repair it after the Lord Xeen destroyed it to prevent the Xeenslaying sword from being used on him. you could buy the castle and then upgrade it with mega tokens or somethings. This was before morrowind came out, pretty sure, since bethesda had just released that atrocity they called battlespire and morrowind wasnt a glint in their eye yet. World of Xeen was a fair bit older than people think.
On a related note.. I am looking for maps for mm2, cause, i am just way too lazy to be actually makign my OWNmaps, cause.. reasons.. i am lazy. Does anybody know a still functional site that actually has sorted mm2 maps that are anotated? the clue book such so much eggs in this regard