"Story" or "Tactics" or "Simulation"
It's about the creative/play agenda at work in them wanting to do this?
If it's about "story", having a home and family etc., then don't sweat the costing/taxes and book-keeping stuff. Make sure the household staff have names, go all "upstairs/downstairs" on them.
If it's about being "realistic" then the more detailed taxes, costs, book-keeping etc. come into it.
If it's about "having a defensible stronghold for when the bad guys come", well then, as said above 3.5 is a problem. It's difficult for a PC to finance a residence that is secure, or even provides a decent amout of guaranteed warning time, within the expected wealth limits etc. etc. Even moreso to have that end up then looking/feeling like historical structures the player may be imagining or that many modules give you (nice bay windows with a view of river?). Some of the Ravenloft sets have beautiful stock card images and floorplans you can use for example. The solutions are there in rules with permanent spells etc etc. but create costs or assumptions that when reverse-engineered back for the bad guys make the game not work. The game is about being in a dungeon. Stronghold Builders Guidebook is a valiant effort but expensive for PCs.
All depends on this being your thing to run as well.
It's about the creative/play agenda at work in them wanting to do this?
If it's about "story", having a home and family etc., then don't sweat the costing/taxes and book-keeping stuff. Make sure the household staff have names, go all "upstairs/downstairs" on them.
If it's about being "realistic" then the more detailed taxes, costs, book-keeping etc. come into it.
If it's about "having a defensible stronghold for when the bad guys come", well then, as said above 3.5 is a problem. It's difficult for a PC to finance a residence that is secure, or even provides a decent amout of guaranteed warning time, within the expected wealth limits etc. etc. Even moreso to have that end up then looking/feeling like historical structures the player may be imagining or that many modules give you (nice bay windows with a view of river?). Some of the Ravenloft sets have beautiful stock card images and floorplans you can use for example. The solutions are there in rules with permanent spells etc etc. but create costs or assumptions that when reverse-engineered back for the bad guys make the game not work. The game is about being in a dungeon. Stronghold Builders Guidebook is a valiant effort but expensive for PCs.
All depends on this being your thing to run as well.