A while back you were able to get that expansive part (i forgot the name,
gave up tinkerin a long long time ago after mastering) of the aqualung from
critters, it was some type of shark in oot i believe. So yes it WAS possible
to max out tinkering at relative low cost since you dont need to buy what is
needed. And 400pp was too low (unless you can sell everything you make at
good price), more like a few thousand plats. Since then the aqualung parts
was removed from the sharks i believe, so i doubt it will be possible to get
to 200 at this low cost nowdays.

Gagaliya Ba'La'Boom at Bristlebane
Gnome wizard of the 50th circle
Retired master tinker

P.S. why the hell would ANYONE want to bother with tinkering it is a waste of
15k+ cash with no rewards, hopefully they will fix it up sometime like with
jewelry and alchemy...should wait till then...my opinion anyway