Building a LEGO 12V steam engine: Acquiring the bricks 

The common parts are a mix, I didn't buy them specifically from the 80s but I tried to use as many older parts as I could by selecting ones with pip marks, older mold designs, old red, etc

I plan on it eventually!

Glad you're interested in getting into 12V! To get a simple loop (1 starter train set, a transformer, and maybe some extra track) you can probably keep it under $300 (maybe $200 if you get a simple set). However the points and signals add up pretty quickly ($50 per point, $80 per signal). I've spent an unholy amount on my entire collection ($5,000+) but I do try to get sets in really nice condition, such as my 7760 with a complete box and mint sticker sheet. If you want, say, a decent layout and you don't care about getting boxed sets, here's an example of price breakdown: 4 points: $200 total 2 signals: $160 total 1 decoupler: $100 2 train sets: depends which you get but say $600 total Extra track + transformer: say $50 That would cost about $1100 total. Again though, it's all up to you and how many trains / remote accessories / supplemental sets you want. The entry point for a super simple loop of track is around that $200-300 mark.

@@Reker1million thanks a lot for answer.

No problem! Happy to help. Let me know if you have any other questions.