What would be a general estimate for what a basic artificer's (as well as Masterwork) lab be ? (magic item creation)
The Advanced Race Guide has a Portable Artificer's Lab for removing some of the penalties for crafting while travelling, which is 300gp and weighs 40lbs.
The ARG also has an Arcane Family Workbook (300gp 3lbs) which debatably could be considered a masterwork tool in regards to magic item creation.
Another source for potential pricing is Ultimate Campaign, under Chapter 2 Downtime for buildings it has an Exotic Artisan building that references being used for a creator of magic items, the only room possibly covering that aspect would be the Artisan's Workshop which has a cost of 360gp, the only problem with this room being that it states it only covers one Craft skill.