You have 2 choices with bases:
- it cost you 10'000 caps, you have to bring material to build the base (not very hard but need time) and you can place the base where you want!
Only depot, Scrapheap, Outpost and Trapper camp are available.
- it cost you more (30K, 50K, 130K, etc...): no need to bring material but you can't place the base. It will be barely around the town where you bought it, but can be too far to make the base interesting.
I advice you to do it only if you want a Gas station, Caves or a Bunker because you can't build them.
Personnally my favourite base it the Depot, because the base is beautiful and not too big; I find Outpost boring with his high number of car places, especially when you spawn on the left with the car.
But Outpost can be a really usefull base, as it's provide meat and lots of brahmin shits (Jet component)
By the way it's not 10 car per location; it's something like 6 for Depot and 14 for Outpost.