proceedings are way too complex to even think of this.
e.g. a suzuki worth 150K gets pricy as much as 215K when used as taxi. cuz the route/permit issues make it so valueable. like first u need to get it physically inspected (engine/chassis no.) then fitness certificate required and so on and so forth. though procedures are fairly simple, but the whole process is complex and cumbersome.
legally, u need to get vehicle reg. in the city where u live/work for more than one year or so ( i exactly dont remember the duration). so u need to prepare all the doc required to prove this thing and this causes pain in ...whatever.
therefore i suggest u, dont buy vehicles of other cities with the intention that u may get their reg changed whenever u 'd like to. process regarding change of Post Offices/token in some cases has proved lengthy and painstaking.