A turbo 180b i built a few years back,

rb20det turbo $450
Supra cooler plus piping $250
Falcon webber, adapter and gas hat $100
2nd hand vl fuel pump and r/r regulator $120
Cheapo boost gauge $30
Cheapo pod filter $30
Misc hosing etc $100

Car used standard dump pipe into standard exhaust, original manifold modded to suit t3 flange, stock motor and inlet manifold, stock clutch and drive train.
For just over $1000 bucks it went significantly harder on stock 7psi


Also it dosnt count because its a mini but same principles, my first car.

Toyota ct12 turbo $140
Boost gauge (tyre pressure gauge) $20
Misc piping and hosing $100

Car used suck through setup with original su carby, standard everything, already had 2" exhaust. Used a su carby lathed into a throttle body mounted after compressor outlet to avoid sucking oil out of turbo seals and the su in front of turbo had no butterfly or choke. Dodgy as custom manifolds made from my neighbours old fence scrap and me learning on an arc welder. Oil drain back into side valve cover as high mount turbo. Ran standard boost and was enough to pick the front up on boost and spin first just accelerating, i hope this enspires others to do some cheap turbo setups