How do you handle spell research / magic item creation without a stronghold?

[Mazirian]

I noticed that the rules say that a Magic-User can undergo research using either a tower he/she built at 9th level or a laboratory, but rules are only given for the former. I know I could just give the player some arbitrary cost to construct a lab, but I think I would like more nuance. Any advice?

[chiisu81]

I interpret it as the Magic-User using someone else's (existing) lab...

[Dimirag]

Starting MUs tend to be under a master tutelage, they could use that lab, or rent one (how much will depend on the lab, its owner, etc)

An Alchemist's Lab cost 500gp and works only for the creation of potions and some magic items, maybe you can create from there, maybe give the lab a level (can only research spell of equal or lesser level) and an associated cost, then add the alchemy lab for potions and another expansion for some other magic item creation

[Solomoriah]

Stronghold creation rules could be used to build a smaller facility, perhaps in a city, as a laboratory. Better yet, buy an old decrepit building and upgrade it using the same rules (at a discount of course, and maybe there's a dungeon under it...)

[Tazer_The_Yoot]

Or repurpose an abandoned shack or emptied out Ogre's lair in the wilderness if you're really cheap and antisocial. (Two traits of most Magic-Users I know.)